The Strange Stories test - Springer Link
Eur Child Adolesc Psychiatry (2005) 14:73–82 DOI 10.1007/s00787-005-0434-2
Nils Kaland Annette Møller-Nielsen Lars Smith Erik Lykke Mortensen Kirsten Callesen Dorte Gottlieb
Accepted: 20 October 2004
N. Kaland () Lillehammer University College Faculty of Social Sciences Gudbrandsdalsvegen 350 2624 Lillehammer, Norway A. Møller-Nielsen · K. Callesen The Danish University of Education Dept. of Psychology and Special Education Emdrupvej 101 2400 København NV, Denmark L. Smith University of Oslo Institute of Psychology Pb. 1094 Blindern 0317 Oslo, Norway E. L. Mortensen Dept. of Health Psychology Institute of Public Health University of Copenhagen Blegdamsvej 3 2200 København N, Denmark
ORIGINAL CONTRIBUTION
The Strange Stories test A replication study of children and adolescents with Asperger syndrome
D. Gottlieb Rehabilitation Center for Children with Acquired Brain Injury Geelsgårdskolen Kongevejen 252 2830 Virum, Denmark
■ Abstract The aim of the present study was to assess the ability of 21 children and adolescents with Asperger syndrome (AS) of normal intelligence to infer mental states in a story context using Happé’s [15] Strange Stories test. The participants in the AS group were compared with an age-matched control group (N = 20) of normally developing children and adolescents on a test of social understanding. The test material comprised social communication such as Pretence, Joke, Lie, White Lie,
Introduction
■ Key words Asperger syndrome – autism spectrum disorders – Strange Stories test – theory of mind – social understanding
dysfunctions associated with the disorder are in keeping with much variability in personality [35]. The condition was termed after the Austrian physician Hans Asperger [2], who described a number of cases with clinical features resembling Kanner’s description of autism [23]. However, Asperger’s description differed from Kanner’s in that speech was less commonly delayed, motor deficits and clumsiness more common [10], the onset of the disorder somewhat delayed, and the initial cases were all boys [43]. Asperger also suggested that similar problems could be observed in family members, particularly among the fathers. However, the validity of AS as distinct from other pervasive developmental disorders remains controversial [8, 11–13, 24, 26, 30, 37, 41, 44].
ECAP 434
Asperger syndrome (AS) is a pervasive developmental disorder (PDD) included in the ICD-10 [46] and the DSM-IV classification [1]. During the last two decades the syndrome has been included in the category of autism spectrum disorders – a cluster of developmental disorders characterized by impairment in social interaction, verbal and non-verbal communication and flexibility, and the presence of idiosyncratic isolated interests. According to ICD-10 and DSM-IV there is no history of language delay,and intelligence is in the normal or near normal range. Individuals with AS have an increased risk of various personality problems, and the neuropsychiatric
Figure of Speech, Misunderstanding, Persuasion, Irony, Double Bluff and Contrary Emotions, Appearance/Reality and Forgetting. As compared to the controls, the participants in the AS group performed less well on these tasks, and answered fewer correct mental state inferences, but performed well on a physical state control task. This study supports the main finding of earlier studies, showing that even individuals with AS of normal intelligence have problems in using mental state terms context-appropriately when tested on the Strange Stories test.
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It seems that even relatively able individuals with high-functioning autism and AS have difficulties appreciating non-literal speech, such as irony, jokes, white lies, metaphorical expressions, and indirect requests. An impairment of the social understanding of non-literal utterances has been demonstrated on the Strange Stories test [15, 20]. In this test children and adolescents with AS of normal intellectual abilities are presented with a set of stories about everyday situations where people say things they do not literally mean. In real life, differential motivations may underlie people’s utterances. For example, someone receiving a birthday present may say, “It’s lovely, thank you. It’s just what I wanted”. This could be said either because it was lovely and they really did want it, or it could be said politely to spare the other person’s feelings. The Strange Stories test was constructed so that the motivation behind an utterance would generally be interpreted by normally developing persons in just one way. Happé [15] recruited participants of differential theory-of-mind abilities and found that even the most able participants with autism tended to give context-inappropriate mental state explanations and thus failed to use a context-appropriate interpretation of an utterance [15, 16]. The Strange Stories test comprises contextually embedded and realistic theory of mind tasks, including simple accounts of events related to the various motivations underlying everyday utterances that are not literally meant. There have been attempts at independent replication of the Strange Stories test, showing that individuals with high-functioning autism and AS were impaired in their ability to answer questions requiring mind-reading abilities. Jolliffe and Baron-Cohen [20] used 18 of the 24 stories and also added a new control task. Heavey, Phillips, Baron-Cohen and Rutter [18] used six of the mentalistic stories and two of the control/ physical passages. In the present study the original stories were employed and for comparison purposes a new physical state control task was introduced. The aim of the present study was to assess whether relatively intelligent children and adolescents with AS would show any substantial impairment in social understanding when assessed on the Strange Stories test and whether they would pass the physical state control task. The prediction was that they would have more problems with the former than with the latter. A normally developing control group was included.All participants were tested on a standard first-order and a second-order false belief task.1 1 All participants passed standard false belief tasks, aside from one participant in the AS group, who failed a first order false belief task (the “Smarties task”) [32] and another participant in the same group, who did not pass a standard second order false belief task (the “Birthday-present task”) [38].
Method ■ Participants The stories were given to children and adolescents with AS (N = 21) with verbal intelligence within the normal range, and to a normally developing control group (N = 20). The participants in the AS group were recruited from Kasperskolen in Copenhagen – a special school for children and adolescents with Pervasive Developmental Disorders – and from the Centre for Autism in Copenhagen. They had been diagnosed independently in clinical settings according to the ICD-10 criteria for AS by experienced psychologists and child psychiatrists. The diagnosis of AS was only given when there was diagnostic agreement between the psychiatrists and the psychologists. In addition, the participants in the AS group had been assessed on ADI-R [28] and on ADOS [27]. The diagnosticians had no knowledge of the purpose or the design of the study. Thus, the selection of the participants was as stringent as possible, given the nosologically controversial diagnosis of AS.As males are over-represented [7] and females probably have a somewhat different clinical symptomatology from males [11], only the former were included in the current study. The controls participating in this study were volunteers recruited from different schools in Copenhagen.At the time of the study they had no known history of developmental lag or disorder. The two groups were matched on gender, age and parental socio-economic status (SES).The participants in the control group scored significantly higher on the WISC-III [42] and were slightly younger than the participants in the AS group. The importance of these group differences was analyzed in two ways: Firstly,the full groups analysis of covariance was conducted with verbal IQ and age as covariates (adjusting for full-scale IQ essentially showed the same results as adjusting for verbal IQ). Secondly, 13 AS index cases were individually matched to 13 control subjects on age and full-scale IQ; the matching was performed in such a way that the lowest functioning AS participants and the most intellectually able controls were excluded. Characteristics of the participants are shown in Table 1. The statistical analysis showed no significant age difference between the two groups (F[1,39] = 0.08, p < 0.78). All participants were within the normal IQ range (i. e.,VIQ > 85) when tested on the WISC-III. However, the control group performed significantly better than the clinical group on verbal IQ (F[1,39] = 11.48, p = 0.002), performance IQ (F[1,39] = 10.64, p < 0.002), and full-scale IQ (F[1,39] = 13.25, p < 0.001). Analysis of questionnaires, completed by the participants’ parents, revealed no significant group differences on level of parental education (F[1,38] = 0.02, p = 0.90), and parental occupational experience (F[1,38] = 1.22, p = 0.28). Two of the participants in the AS group were
N. Kaland et al. The Strange Stories test. A replication study of children and adolescents with Asperger syndrome Table 1 Participant characteristics: chronological age, verbal IQ, performance IQ, and full Scale IQ (mean, SD and range) Variable
Asperger group (N = 21)
Control group (N = 20)
F
p
CA Mean (SD) Range
15.86 (3.22) 10:2–20:4a
15.57 (3.28) 9:6–20:9
0.08
0.78
VIQ Mean (SD) Range
111.4 (16.92) 90–138
126.4 (10.57) 104–144
11.48
0.002
PIQ Mean (SD) Range
98.3 (14.36) 74–123
113.1 (14.71) 78–136
10.64
0.002
FSIQ Mean (SD) Range
106.4 (16.80) 81–134
122.7 (11.20) 102–142
13.52
0.001
a Years:Months
left-handed as opposed to four in the control group. All participants were free of medication at the time of testing.
■ Materials The tasks consisted of 24 short mentalistic stories and 13 physical control stories. The mentalistic stories – the Strange Stories test [15] – consisted of 24 short vignettes. There were two examples of each story type, comprising Pretence, Joke, Lie, White Lie, Misunderstanding, Persuasion, Appearance/Reality, Figure of Speech, Irony, Double Bluff, Contrary Emotions, and Forgetting. The mentalistic stories were accompanied by two, and for one story type, three test questions: the comprehension question, which usually took the form “Was it true, what X said?” and the justification question “Why did X say that?” The physical2 state control task [21] was presented in order to assess the understanding of physical events and check the generality of any comprehension deficit that might emerge irrespective of story content. The physical control stories had just one question, asking why a particular action had been carried out. Examples of the experimental stories are given in the Appendix.
■ Procedure The participants were tested in a quiet room in school or at the Centre for Autism. The stories were introduced as 2 The physical control task in the present study consisted of
a set of 13 stories, which were separated into a physical state and a mental state section. Only the physical state section was used as a control task.
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follows: Here are some stories, and some questions. I’m going to read the stories and I’d like you to listen carefully and then answer the questions at the end of each story.” The story was read to the participant – except in a few cases where the person preferred to read the story himself. The story remained in front of the participant throughout the session. At the end of the story the person was asked the test questions. The first question, “Was it true, what X said?” was a test of linguistic comprehension. If the answer was wrong the story was read out again until the person answered correctly or justified his answer. The answers to these questions were recorded but not further analyzed. The second question, the justification probe, “Why did X say that?” was then asked, and the participant’s answer was recorded in full (taped and written down on scoring sheets) for later analysis. Positive comments were made throughout the testing session to encourage the participant, but no feedback was given about the correctness of the answers. Administration was adjusted according to the requirement of each participant. Testing time varied from approximately 30–40 minutes to 1 hour. The participants used at least two, in some cases more, sessions to complete the test. Breaks with refreshments were given as needed. Prompt questions were given only if the participants provided no answers or inappropriate answers to the questions. For example, in the White Lie story a participant might be reminded that Peter did not like his aunt’s hat, by the additional prompt question “What did Peter think of the new hat?” (See story example in the Appendix). The participants in the control group received the stories largely in the same way as those in the AS group. The stories, translated into Danish, were intended to be unambiguous with only one explanation reasonably appropriate for the justification of why a particular action occurred. The stories were presented in random order, and two examples of one story type never followed each other.
■ Scoring The justifications were scored as either involving mental states or physical states. Mental state justifications included all those that referred to thoughts, feelings, desires, traits, and dispositions. They included terms such as like, want, happy, cross, afraid, know, think, joke, pretend, expect, lie, hurt, and to fool someone. Physical state justifications were those that referred to non-mental events, physical appearances, physical events, action of objects, and outcomes. They included terms such as big, looks like, is shaped like, get rid of, to sell, because of the X (object), to not get X (physical outcome), put in jail, told off, have a filling etc.).
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In accordance with the current scoring procedure for this task [17] participants’ answers to the justification question were scored as a 2 for a fully correct answer, 1 for a partially correct justification, and 0 for an incorrect justification. A correct justification was in most cases a mental state explanation. In some cases it could also be correctly answered with a physical state explanation. For example, in the Joke story where a boy calls a dog an elephant (see appendix), this could correctly be explained by the physical justification, “the dog is big like an elephant”,or by the mental state justification,“He’s just joking”. Similarly, an incorrect justification could be incorrect in two ways: in the physical sense, an answer that was contextually irrelevant, such as “the dog is not an elephant”and in the mental sense,“because the boy is lying”. A justification could be rated as incorrect because it involved errors about the facts given in the story, or because of an inference that was contextually inappropriate as a reason for the story character’s utterance. For example, in one of the Lie stories, in which a boy lies to his mother about his toothache because he does not want to go to the dentist, justifications like “He wants to tell his mother the truth” or “He is just joking” would be scored as incorrect because they include a factual error; in the context of this story it is not appropriate to interpret his utterance as telling the truth or joking. As responses sometimes turned out to be neither quite correct nor quite incorrect, they were rated as partially correct. For example, in one story an old lady misunderstands a stranger coming towards her, just wanting to ask her what time it is. She gives away her purse because she misunderstands his intention and fears that he will rob and hurt her. Answers to the “why” question such as “she did not know what he wanted” and the like were then scored as partially correct. The participants were scored according to their correct justification. That is, if a person provided one correct answer and one inappropriate answer, the correct answer was employed.Similarly,if a participant’s answer appealed both to a physical and a mental state, the justification was scored as a mental state.
■ Inter-scorer-reliability Two persons administered the stories, and subsequently one of these acted as a first rater. A third person, not being involved in the testing process, acted as a second rater. Judging whether an explanation on the justification question was appropriate or not is clearly subjective and made assessment of inter-scorer reliability necessary. In cases of disagreement, for example when the first rater considered the answer correct, whereas the second rater
considered the same answer partially correct, or incorrect, the mean of the two values was computed. For the physical control stories kappa was 0.76. For the mentalistic stories the degree of concordance was high, as only six justifications on the mentalistic test (out of 984 responses) received discordant ratings. Four of these were given by the participants in the AS group and two by those in the control group.
Results On the Strange Stories test the participants in the AS group answered the comprehension question (“Is it true . . .?”) essentially in a correct way. On rare occasions when a participant made an error, the story was read out again, until he answered correctly or justified his answer. On the “why” questions the participants in the AS group earned an average of 40.8 points on total correct/partially correct answers, whereas the control group received an average of 45. 1 points, out of 48 possible (Table 2). Comparison (ANOVA) showed a statistically significant difference between the groups on this task; a covariance-analysis with control for age and FSIQ showed that the difference was still statistically significant (p = 0.004) (cf. Table 2). When using a more strict coding procedure with fully correct versus partially correct/incorrect responses, there was a significant difference (ANOVA) between the groups (F[1,39] = 22.82, p < 0.0001); after control for age and FSIQ (F[1,37] = 10.91, p = 0.002). With the same coding procedure a paired t-test showed a statistically significant difference between the 13 AS index cases and the 13 matched control subjects (t[12] = 3.09, p = 0.009). When using the standard scoring procedure, outlined in the method section, there was still a significant difference between the groups on this measure (cf. Table 3). The participants in the AS group needed significantly more prompt questions than the controls in order to answer the justification questions on the Strange Stories – a mean of 6.5 as compared to the control group’s 0.8. The difference was statistically significant after control for age and FSIQ (cf. Table 2). On the physical control task the mean score of the participants in the AS group was 23.9 (out of 26 possible), as opposed to 24.8 in the control group. An analysis of variance (ANOVA) showed that the difference between the two groups was not statistically significant; control for age and FSIQ, however, yielded statistically significant differences between the two groups on this task (F[1,37] = 4.43, p < 0.05). When using a coding procedure with fully correct versus partially correct/incorrect responses the difference between the groups was not statistically significant when controlling for age and FSIQ (F[1,37] = 2.39, p = 0.13). A paired t-test showed no
N. Kaland et al. The Strange Stories test. A replication study of children and adolescents with Asperger syndrome Table 2 Results on the Strange Stories test and the Physical Control task – observed (SD) and adjusted means, F- and p-values
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Variable
Asperger group (N = 21) Mean (SD)
Control group (N = 20) Mean (SD)
F
p
Total score correct/partially correct justifications (max = 48): Observed mean (SD)a Adjusted meanb
40.76 (3.36) 41.49
45.08 (2.54) 44.31
21.33 9.34
< 0. 0001 0.004
Total number of mental state justifications: Observed mean (SD) Adjusted mean
20.14 (1.56) 20.36
21.15 (1.50) 21.02
4.45 1.67
0.04 0.20
Total number of physical state justifications: Observed mean (SD) Adjusted mean
3.86 (1.56) 3.64
2.85 (1.50) 2.98
4.45 1.67
0.04 0.20
Prompt questions: Observed mean (SD) Adjusted mean
6.52 (4.59) 6.41
0.75 (1.68) 0.89
28.04 19.48
< 0.0001 0.0001
Physical control task: Observed mean (SD) Adjusted mean
23.88 (1.72) 23.79
24.80 (1.36) 24.90
3.57 4.43
< 0.07 < 0.05
a Observed means: df = 1.39; b Adjusted means (results of covariance analysis): df = 1.37
Table 3 Results on the Strange Stories test when matching 13 pairs of participants in the Asperger and the control group on age and intelligence
Variable CA (months) VIQ PIQ FSIQ Performance, physical control task Performance, Strange Stories test Prompts, Strange Stories test
Asperger group Mean (SD)
Control group Mean (SD)
Difference
t
15.86 (2.67) 121.00 (13.70) 107.46 (9.09) 117.15 (11.08) 23.92 (1.32)b
15.91 (2.54) 123.62 (10.91) 108.08 (13.49) 118.92 (10.36) 24.69 (1.44)
–0.05 –2.62 –0.62 –1.77 –0.77
0.05a 1.10 0.23 1.77 1.33
0.96 0.29 0.82 0.10 0.21
41.92 (2.98)
44.65 (2.91)
–2.73
2.64
< 0.02
7.00 (4.73)
1.08 (2.02)
5.92
3.98
p
0.002
a df for paired t-test = 12; b Matching variables: Chronological age and full-scale IQ
significant differences between the 13 AS index cases and the 13 matched control subjects on the physical control task (t[12] = 1.33, p = 0.21, cf. Table 3). Further, the participants in the AS group did not need significantly more prompt questions than the controls on this task when using the standard scoring procedure [17], controlling for age and FSIQ (F[1,37] = 0.22, p = 0.64). The covariance analysis of total number of mental state justifications provided on the Strange Stories test showed that the participants in the AS group did not give significantly fewer such answers as compared to the participants in the control group (cf. Table 2). The analysis of the 13 matched pairs of participants also showed no significant difference between the groups on this variable (t[12] = 1.67, p = 0.12). As to correct mental state justifications the participants in the AS group performed less well than the par-
ticipants in the control group (p < 0.002). The AS participants provided, as one could expect, significantly more partially correct mental state justifications (= 0.005), but not significantly more incorrect mental state justifications than the participants in the control group (p < 0.36) (cf. Table 4). The relationship between participants’ performance on the Strange Stories test and verbal IQ, age and control task was examined. In the AS group there was a relatively strong correlation between performance on the Strange Stories test and verbal IQ (r = 0.60, p < 0.01). In the control group this association was weak (r = 0.19, ns). Performance on the Strange Stories test was significantly related to chronological age in the control group (r = 0.56, p 0.05), but not in the AS group (r = 0.18, ns). There was no significant correlation between performance on the Strange Stories test and the physical control
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Table 4 Number of correct, partially correct, and incorrect justifications – observed and adjusted means Variable
Asperger group (N = 21) Mean (SD)
Control group (N = 20) Mean (SD)
F
p
Correct mental state justifications: Observed mean (SD)a Adjusted meanb
15.48 (2.47) 15.89
19.00 (2.49) 18.57
20.23 10.67
< 0.0001 0.002
Correct physical state justifications: Observed mean (SD) Adjusted mean
2.62 (1.32) 2.74
2.20 (1.28) 2.07
1.06 2.01
0.31 0.16
Partially correct mental state justifications: Observed mean (SD) Adjusted mean
3.52 (1.57) 3.45
1.90 (1.07) 2.07
14.83 8.83
< 0.0001 0.005
Partially correct physical state justifications: Observed mean (SD) Adjusted mean
1.10 (1.04) 0.85
0.5 (0.89) 0.75
3.85 0.10
0.06 0.75
Incorrect mental state justifications: Observed mean (SD) Adjusted mean
1.00 (1.05) 0.8
0.35 (0.59) 0.6
5.91 0.84
0.02 0.36
Incorrect physical state justifications: Observed mean (SD) Adjusted mean
0.29 (0.46) 0.26
0.05 (0.22) 0.08
4.24 1.69
0.05 0.20
a Observed means: df = 1,39; b Adjusted means (results of covariance analysis): df = 1,37
task in either group: AS group (r = 0.17, ns) and control group (r = 14, ns). These findings should be treated with caution, however, given the small sample and the number of correlations computed. As shown in Table 5, the participants in the AS group provided more context-inappropriate mental state inferences, as compared to the participants in the control group. All participants in the AS group provided at least one such answer, 81% two or more, 57% three or more and 28% four or more context-inappropriate answers. This tendency was most apparent on the story types
Joke, Figure of Speech, and Irony. The participants in the control group provided relatively few such answers. As mentioned above, the stories were intended to be unambiguous, with only one explanation reasonably appropriate for the justification of why a particular action occurred. However, on the story type Forgetting quite a few participants in both groups provided alternative interpretations of the story persons’ utterances. As far as the answers provided on these stories could be a reasonable response to the justification question, they were scored as partially correct.
Table 5 Context-inappropriate mental state justifications on the Strange Stories – Asperger and control group
Discussion
Asperger group (N = 21)
Control group (N = 20)
Story type
Number
Percentage
Number
Percentage
Pretend Joke Lie White lie Figure of speech Misunderstanding Double bluff Irony Persuasion Contrary emotions Appearance/reality Forget
1 10 1 4 6 2 1 11 2 3 4 0
2.4 23.8 2.4 9.5 14.3 4.8 2.4 26.2 4.8 7.1 9.5 –
0 2 0 0 1 0 0 2 0 1 0 0
– 5.0 – – 2.5 – – 5.0 – 2.5 – –
The present results support the general experimental prediction: the theory of mind measures within the Strange Stories test paradigm revealed group differences, suggesting that relatively able individuals with AS have problems in interpreting simple stories about everyday events. The results on the mentalistic task were largely consistent with the finding of Happé [15] and Jolliffe and Baron-Cohen [20]. There was no statistically significant difference between the two groups on the physical control task when using a more strict scoring procedure and after the matching of the 13 AS and 13 control participants. This suggests that the current and more lenient scoring procedure for the Strange Stories test [17], described in the method section, may have slightly reduced the differences between the groups. The problems experienced by the participants in the clinical
N. Kaland et al. The Strange Stories test. A replication study of children and adolescents with Asperger syndrome
group were also evident in their need for more prompt questions than the controls when answering the mental state justifications, whereas they did not need significantly more prompt questions on the physical state control task. Although the participants in the AS group provided significantly less correct mental state justifications than the controls on the Strange Stories test, they did not yield significantly less total mental state justifications than the controls when differences in IQ between the groups were partialled out. This is in accordance with earlier findings [15, 20]. Several studies have shown that individuals with high-functioning autism or AS pass standard theory of mind tasks [e. g., 15, 21] – as was also the case in the present study. However, when more ‘advanced’ tests of theory of mind with a more complex social context were used, these individuals evidenced impairment in the area of social cognition [21]. In the clinical group there was also a relatively strong association between verbal IQ and performance on the Strange Stories test, suggesting that mentalizing deficits in individuals with AS are related to their intellectual competence [33]. Despite the covariance control analysis, an effect of IQ cannot be ruled out completely. However, when excluding the participants in the AS groups who obtained lower IQ scores than the lowest value of the control group, there was still a statistically significant group difference on the mentalistic task but not on the physical control task. This type of comparison yields more unambiguous results due to control of differential intellectual abilities. Although many of the participants in the AS group eventually provided correct, or partially correct justifications, often after one or more prompt questions, they often revealed idiosyncratic ways of interpreting everyday situations and tended to use mental state terms context-inappropriately. For example on the “why” question of one of the Figure of speech stories, where a girl coughs and coughs and her father says she must have a frog in her throat, one participant in the AS group answered that her father says it “. . because it’s much so, a sort of synonym or saying – as the destruction of Jerusalem”. Peculiarities were also found in one of the Joke stories where the story character says that the visitor’s big dog is an elephant. To the question of why they said this, several participants in the AS group stated the fact that the dog was not an elephant. But as one of them pointed out: “Exaggeration makes understanding easier”. Furthermore, to their more or less correct answers they tended to provide additional information of little relevance. The idiosyncratic and context-inadequate responses provided by the participants in the AS group, when still demonstrating some mentalizing abilities, could also be related to a weak drive for ‘central coherence’. This con-
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cept refers to a tendency to process contextual information in a piecemeal fashion, as opposed to global processing [9]. Individuals with autism spectrum disorders are hypothesized to have a specific impairment in extracting meaning in context, and this tendency may partially explain the many context-inappropriate and peculiar responses provided by the participants in the AS group [15]. However, a weak drive for ‘central coherence’ should be distinguished from a failure to attribute mental states [16]. Another observation was that some of the participants in the AS group tended to give literal, physical interpretations of social events. Their difficulty in attributing context-appropriate mental states in the test situation seemed to make a physical explanation the preferred or easier option. Even when they recognized the difference between an imaginary representation and a real world situation they often emphasized this difference by saying “. . but in the real world it is not true”. Thus, the ‘cognitive style’, at least of the present participants, appeared to be more ‘physical’ than ‘mentalistic’. The story types Joke, Figure of Speech, Irony, and Contrary Emotions proved to be the most difficult ones for the participants in the AS group. However, some of the younger participants in the control group had also problems with these story types. Interestingly, many individuals in the clinical group performed relatively well on the double bluff stories, which require a third order theory of mind (i. e. an extra level of embedding), but less well on the irony stories, which also require a thirdorder theory of mind [14]. One possible explanation for this difference may be that the process of interpreting irony goes through other cognitive “routes” than working out an answer to a double bluff [3, 4, 6]. Hermelin and O’Connor [19], who invoked the concept of “logicoaffective” states, have argued that some individuals with autistic spectrum disorders are able to use cognitive mechanisms to deal with problems that are usually dealt with by affective processes. The use of cognitive rather than affective processes could also, as Bowler [3] suggests, result in a slowing of responses, and a disruption of the subtle timing of social interactions, thereby making the person seem odd to other people in social situations. Could memory or language problems represent the underlying cause of the AS persons’ difficulties on the Strange Stories test? In a recent study of high-functioning individuals with autism or AS, Bowler, Gardiner & Grice [5] found that their memory functions were relatively intact as compared with normally developing control persons. Matron, Morasses & Belleville [29] found no amnesic or semantic deficit in the memory of highfunctioning individuals with autism relative to normal controls. According to these studies it seems less likely that memory problems could have accounted for the im-
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paired mental state attribution found in individuals with AS in the present study. Although a receptive language problem cannot be ruled out, the difficulties experienced by the participants in the clinical group were probably not caused by lack of linguistic comprehension, since they did not evidence significantly more errors than the controls on the comprehension questions. Another finding that supports the view that a language problem can hardly be the cause of the difficulties experienced by the participants in the AS group is the fact that the groups did not perform differently on the physical control stories. As Sperber and Wilson [36] argue, language and communication are different and logically separate phenomena; language is a grammar-governed representational system and may be relatively intact in individuals with AS [14]. However, individuals with AS exhibit abnormalities in the social use of language [25, 34], which may primarily be related to their cognitive (theory of mind, executive functions) deficits [31, 39, 40]. Wing suggests that individuals with AS are generally slow in the test situation and that marks are lost on IQ tests because of their inability to work fast on timed items [45]. Some evidence for this view was found when the response times of the participants in the present study were recorded on another ‘advanced’ test of theory of mind, the Stories from Everyday Life [21]. The participants in the AS group were significantly slower than the normally developing persons in the control group, especially on mental state inference tasks [22]. The results of our use of the Strange Stories test suggest that the participants in the AS group showed significant impairment of social understanding, as compared to normally developing control persons. Conceptualized as a dimensional category and permitting considerable variation in personality [35], AS is arguably the most puzzling among the variants on the autistic spectrum. The combination of social ineptness and relatively good verbal ability remains one of the challenges to theories of social cognition. Future research, based on more refined tests and study design, should address this challenge.
Appendix
Story type: Joke Today James is going to Claire’s house for the first time. He is going over for tea, and he is looking forward to seeing Claire’s dog, which she talks about all time. James likes dogs very much. When James arrives at Claire’s house Claire runs to open the door, and her dog jumps up to greet James. Claire’s dog is huge; it’s almost as big as James! When James sees Claire’s huge dog he says, “Claire, you haven’t got a dog at all. You’ve got an elephant!” Is it true, what James says? Yes/No/Don’t know Why does he say this? Story type: White lie One day Aunt Jane came to visit Peter. Now Peter loves his aunt very much, but today she is wearing a new hat; a new hat, which Peter thinks is very ugly indeed. Peter thinks his aunt looks silly in it, and much nicer in her old hat. But when Aunt Jane asks Peter,“How do you like my new hat”, Peter says,“Oh, its very nice”. Was it true, what Peter said? Yes/No/Don’t know Why did he say it? Story type: Figure of Speech Emma has a cough. All through lunch she coughs and coughs. Father says: “Poor Emma, you must have a frog in your throat!” Is it true, what Father says to Emma? Yes/No/Don’t know Why does he say that? Story type: Irony Ann’s mother has spent a long time cooking Ann’s favourite meal; fish and chips. But when she brings it to Ann, she is watching TV, and she doesn’t even look up, or say thank you.Ann’s mother is cross and says, “Well, that’s very nice, isn’t it! That is what I call politeness!” Is it true what Ann’s mother says? Yes/No/Don’t know Why does Ann’s mother say this? Story Type: Misunderstanding Late one night old Mrs. Peabody is walking home. She doesn’t like walking alone in the dark because she is always afraid that someone will attack her and rob her. She is really very nervous! Suddenly, out of the shadow comes a man. He wants to ask Mrs. Peabody what time it is, so he walks towards her. When Mrs. Peabody sees the man coming towards her, she starts to tremble and says, “Take my purse, just don’t hurt me”.
■ Examples from the Strange Stories test:
Was the man surprised at what Mrs. Peabody said?
Story type: Pretend
Yes/No/Don’t know
Katie and Emma are playing in the house. Emma picks up a banana from the fruit bowl and holds it up to her ear. She says to Katie,“Look! This banana is a telephone!”
Why did she say that, when he only wanted to ask her the time?
Is it true what Emma says?
Yvonne is playing in the garden with her doll. She leaves her doll in the garden when her mother calls her to come in for lunch.While they are having lunch, it starts to rain. Yvonne’s mother asks Yvonne: “Did you leave your doll in the garden?”Yvonne answers:“No, I brought her in with me”.
Yes/No/Don’t know Why does Emma say this?
Story Type: Forgetting
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Lind, and says that she would like to have her piano tuned. She tells John her address. Some minutes previously a small job John was to do this morning in the concert house had been cancelled. A few minutes later he arrives at Mrs. Lind’s villa.
Is it true, what Yvonne says? Yes/No/Don’t know Why does Yvonne say this?
Question: Why doesn’t Mrs. Lind have to wait a week to have her piano tuned?
■ Physical control story examples The architect Ken Peterson is known as a person rich in ideas. He works with Solnes, a master builder who has his office in the town. He goes to Solnes almost daily with new ideas about how to build bigger and better buildings. The idea rich architect uses steel and glass as construction materials, because they are the materials that can give the most protection against storms and bad weather. With these materials it is possible to build fine, big buildings. Wooden material and roof tiles are well suited for the construction of normal single-floored dwellings, he says. Question: Why doesn’t architect Peterson use wooden material and roof tiles when projecting high buildings? John Frank is 25 years old and tunes all kinds of pianos. He is the only piano tuner in the town, and his clients must normally wait a week before he can do the work they desire. Usually he carries out his work in the homes of the clients. One day an old lady calls him. She presents herself as Mrs. Agnes
David Swenson is broke at the moment, because he has just paid some large bills. One day after filling his old, but well-maintained car with petrol he falls for the temptation of driving off without paying. The attendant at the station is busy with another customer, at the same time his telephone is ringing and a mechanic in the garage is calling him. Questions: Why doesn’t the serving attendant at the station stop Swenson when he drives away after not having paid for his petrol? One late, dark autumn evening the 14 year old Paul is going along some scary town streets with his mother. They have heard and read of people who have been robbed of their money in this area. Earlier that day Paul’s mother has been to the bank and made a withdrawal of 8000 NOK. She has placed the money in an inside coat pocket instead of in her handbag. Her old washing machine broke down for good a couple of days ago, and she has to buy a new one in one of the coming days. Question: Why has Paul’s mother been to the bank and made a withdrawal?
References 1. American Psychiatric Association (1994) Diagnostic and Statistical Manual of Mental Disorders. 4th Edition. Author: Washington, DC 2. Asperger H (1944) Die ‘Autistischen Psychopathen’ im Kindesalter. Archiv für Psychiatrie und Nervenkrankheiten 117:76–136 3. Bowler DM (1992) ‘Theory of mind’ in Asperger’s syndrome. J Child Psychol Psychiatry 33:877–893 4. Bowler DM (1997) Reaction times to mental state and non-mental state questions in false belief tasks by highfunctioning individuals with autism. Eur Child Adolesc Psychiatry 6:160–165 5. Bowler DM, Gardiner JM, Grice SJ (2000) Episodic memory and remembering in adults with Asperger syndrome. J Autism Devel Disord 30: 295–304 6. Bruner J, Feldman C (1993) Theories of mind and the problem of autism. In: Baron-Cohen S, Tager-Flusberg H, Cohen DJ (eds) Understanding other Minds – Perspectives from Autism. Oxford University Press. Oxford, pp 267–291 7. Ehlers S, Gillberg C (1993) The epidemiology of Asperger Syndrome.A total population study. J Child Psychol Psychiatry 34:1327–1350
8. Eisenmajer R, Prior M, Leekam SR, Wing L, Gould J, Ben M, Ong B (1996) Comparison of clinical symptoms in autism and Asperger’s disorder. J Am Acad Child Adolesc Psychiatry 35: 1523–1531 9. Frith U, Happé FGE (1994) Autism: Beyond ‘theory of mind’. Cognition 50: 115–132 10. Ghaziuddin M, Butler E (1998) Clumsiness in autism and Asperger syndrome: a further report. J Intellect Disabil Res 42:43–48 11. Gillberg C (1997) Barn, ungdommar och vuxna med Asperger syndrom – normala, genier, nørder? Bokförlaget Cura. Stockholm 12. Gillberg C (1998) Asperger syndrome and high-functioning autism. Br J Psychiatry 172:200–209 13. Gillberg C, Billstedt E (2000) Autism and Asperger syndrome: coexistence with other clinical disorders. Acta Psychiatr Scand 102:321–330 14. Happé FGE (1991) The autobiographical writing of three Asperger syndrome adults: problems of interpretation and implications for theory. In: Frith U (ed) Autism and Asperger Syndrome. Cambridge University Press. Cambridge, pp 207–242 15. Happé FGE (1994) An advanced test of theory of mind: Understanding of story characters’ thoughts and feelings by able autistic, mentally handicapped and normal children and adults. J Autism Devel Disord 24:129–154
16. Happé FGE (1999) Autism: Cognitive deficit or cognitive style? Trends in Cogn Sci 3:216–222 17. Happé FGE, Winner E, Brownell H (1998) The getting of wisdom: Theory of mind in old age. Devel Psychol 34: 358–362 18. Heavey L, Phillips W, Baron-Cohen S, Rutter M (2000) The awkward moment test: A naturalistic measure of social understanding in autism. J Autism Devel Disord 30:225–236 19. Hermelin B,O’Connor N (1985) Logicoaffective states and non-verbal language. In: Schopler E, Mesibov GM (eds) Communication Problems in Autism. Plenum Press. New York, pp 283–310 20. Jolliffe T, Baron-Cohen S (1999) The Strange Stories Test: A replication with high-functioning adults with autism or Asperger syndrome. J Autism Devel Disord 29:395–406 21. Kaland N, Møller-Nielsen A, Callesen K, Mortensen EL, Gottlieb D, Smith L (2002) A new ‘advanced’ test of theory of mind: evidence from children and adolescents with Asperger syndrome. J Child Psychol Psychiatry 43:517–56 22. Kaland N, Smith L, Mortensen EL (2004) Response times of children and adolescents with Asperger syndrome on an ‘advanced’ test of theory of mind. J Autism Devel Dis 23. Kanner L (1943) Autistic disturbances of affective contact. Nerv Child 2: 217–250
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24. Klin A, Volkmar FR, Sparrow SS, Ciccietti DV, Rourke BP (1995) Validity and neuropsychological characterization of Asperger syndrome – convergance with nonverbal learning-disability syndrome. J Child Psychol Psychiatry 36: 1127–1140 25. Landa RL (2000) Social language use in Asperger syndrome and high-functioning autism. In: Klin A, Volkmar FR, Sparrow SS (eds) Asperger syndrome. Guildford Press. New York, pp 124–155 26. Leekam SR, Libby S, Wing L, Gould J, Gillberg C (2000) Comparison of ICD10 and Gillberg’s criteria for Asperger syndrome. Autism 4:11–28 27. Lord C, Rutter M, Goode S, Heemsbergen J, Jordan H, Manhood L, Schopler E (1989) Autism Diagnostic Observation Schedule: A standardized observation of communicative and social behavior. J Autism Devel Disord 19:185–212 28. Lord C, Rutter M, Le Couture A (1994) Autism Diagnostic Interview-Revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. J Autism Devel Disord 24: 659–685 29. Matron L, Morasses K, Belleville S (2001) A study of memory functioning in individuals with autism. J Child Psychol Psychiatry 42:253–260 30. Miller NJ, Ozonoff S (2000) The external validity of Asperger Disorder: Lack of evidence from the domain of neuropsychology. J Abn Psychol 109: 227–238
31. Ozonoff S, Miller J (1996) An exploration of right hemisphere contribution to the pragmatic impairment of autism. Brain Lang 52:411–434 32. Perner J, Frith U, Leslie AM, Leekam SR (1989) Exploration of the autistic child’s theory of mind: Knowledge, belief, and communication. Child Dev 60: 689–700 33. Prior M, Leekam S, Ong B, Eisenmajer R, Wing L, Gould J, Dove D (1998) Are there subgroups within the autistic spectrum? A cluster analysis of a group of children with autistic spectrum disorders. J Child Psychol Psychiatry 39: 893–902 34. Ramberg C, Ehlers S, Nydén A, Johansson M, Gillberg C (1996) Language and pragmatic functions in school-age children on the autism spectrum. Eur J Disord Commun 31:387–414 35. Soderstrom H, Rastam M, Gillberg C (2002) Temperament and character in adults with Asperger syndrome.Autism 6:287–297 36. Sperber D, Wilson D (1995) Relevance: Communication and cognition. Basil Blackwell. Oxford 37. Szatmari P (2000) The classification of autism, Asperger syndrome, and pervasive developmental disorders. Can J Psychiatry 45:731–738 38. Tager-Flusberg H, Sullivan K (1994) A second look at second-order belief attribution in autism. J Autism Devel Disord 24:577–586
39. Tager-Flusberg H, Baron-Cohen S, Cohen DJ (1993) An introduction to the debate. In: Baron-Cohen S, Tager-Flusberg H, Cohen DJ (eds) Understanding other minds – perspectives from autism. Oxford University Press. Oxford, pp 3–9 40. Tantam D (2000) Adolescence and adulthood of individuals with Asperger syndrome. In: Klin A, Volkmar FR, Sparrow SS (eds) Asperger syndrome. Guildford Press. New York, pp 367–399 41. Volkmar FR, Klin A, Schultz RT, Rubin E, Bronen R (2000) Asperger’s syndrome. Am J Psychiatry 157:262–267 42. Wechsler D WISC-3 (1998) Wechsler Intelligence Scale for Children. Danish translation and adaptation. Danish Psychological Publishers. Copenhagen 43. Wing L (1981) Asperger’s syndrome. A clinical account. Psychol Med 11: 115–129 44. Wing L (1991) The relationship between Asperger’s syndrome and Kanner’s autism. In: Frith U (ed) Autism and Asperger Syndrome. Cambridge University Press. Cambridge, pp 93–121 45. Wing L (1998) The history of Asperger syndrome. In: Schopler E, Mesibov GM, Kunce LJ (eds) Asperger syndrome or high-functioning autism. Plenum Press. New York, pp 11–28 46. World Health Organization (1993) The ICD-10 classification of mental and behavioral disorders. Diagnostic criteria for research. Author. Geneva
Nils Kaland Annette Møller-Nielsen Lars Smith Erik Lykke Mortensen Kirsten Callesen Dorte Gottlieb
Accepted: 20 October 2004
N. Kaland () Lillehammer University College Faculty of Social Sciences Gudbrandsdalsvegen 350 2624 Lillehammer, Norway A. Møller-Nielsen · K. Callesen The Danish University of Education Dept. of Psychology and Special Education Emdrupvej 101 2400 København NV, Denmark L. Smith University of Oslo Institute of Psychology Pb. 1094 Blindern 0317 Oslo, Norway E. L. Mortensen Dept. of Health Psychology Institute of Public Health University of Copenhagen Blegdamsvej 3 2200 København N, Denmark
ORIGINAL CONTRIBUTION
The Strange Stories test A replication study of children and adolescents with Asperger syndrome
D. Gottlieb Rehabilitation Center for Children with Acquired Brain Injury Geelsgårdskolen Kongevejen 252 2830 Virum, Denmark
■ Abstract The aim of the present study was to assess the ability of 21 children and adolescents with Asperger syndrome (AS) of normal intelligence to infer mental states in a story context using Happé’s [15] Strange Stories test. The participants in the AS group were compared with an age-matched control group (N = 20) of normally developing children and adolescents on a test of social understanding. The test material comprised social communication such as Pretence, Joke, Lie, White Lie,
Introduction
■ Key words Asperger syndrome – autism spectrum disorders – Strange Stories test – theory of mind – social understanding
dysfunctions associated with the disorder are in keeping with much variability in personality [35]. The condition was termed after the Austrian physician Hans Asperger [2], who described a number of cases with clinical features resembling Kanner’s description of autism [23]. However, Asperger’s description differed from Kanner’s in that speech was less commonly delayed, motor deficits and clumsiness more common [10], the onset of the disorder somewhat delayed, and the initial cases were all boys [43]. Asperger also suggested that similar problems could be observed in family members, particularly among the fathers. However, the validity of AS as distinct from other pervasive developmental disorders remains controversial [8, 11–13, 24, 26, 30, 37, 41, 44].
ECAP 434
Asperger syndrome (AS) is a pervasive developmental disorder (PDD) included in the ICD-10 [46] and the DSM-IV classification [1]. During the last two decades the syndrome has been included in the category of autism spectrum disorders – a cluster of developmental disorders characterized by impairment in social interaction, verbal and non-verbal communication and flexibility, and the presence of idiosyncratic isolated interests. According to ICD-10 and DSM-IV there is no history of language delay,and intelligence is in the normal or near normal range. Individuals with AS have an increased risk of various personality problems, and the neuropsychiatric
Figure of Speech, Misunderstanding, Persuasion, Irony, Double Bluff and Contrary Emotions, Appearance/Reality and Forgetting. As compared to the controls, the participants in the AS group performed less well on these tasks, and answered fewer correct mental state inferences, but performed well on a physical state control task. This study supports the main finding of earlier studies, showing that even individuals with AS of normal intelligence have problems in using mental state terms context-appropriately when tested on the Strange Stories test.
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It seems that even relatively able individuals with high-functioning autism and AS have difficulties appreciating non-literal speech, such as irony, jokes, white lies, metaphorical expressions, and indirect requests. An impairment of the social understanding of non-literal utterances has been demonstrated on the Strange Stories test [15, 20]. In this test children and adolescents with AS of normal intellectual abilities are presented with a set of stories about everyday situations where people say things they do not literally mean. In real life, differential motivations may underlie people’s utterances. For example, someone receiving a birthday present may say, “It’s lovely, thank you. It’s just what I wanted”. This could be said either because it was lovely and they really did want it, or it could be said politely to spare the other person’s feelings. The Strange Stories test was constructed so that the motivation behind an utterance would generally be interpreted by normally developing persons in just one way. Happé [15] recruited participants of differential theory-of-mind abilities and found that even the most able participants with autism tended to give context-inappropriate mental state explanations and thus failed to use a context-appropriate interpretation of an utterance [15, 16]. The Strange Stories test comprises contextually embedded and realistic theory of mind tasks, including simple accounts of events related to the various motivations underlying everyday utterances that are not literally meant. There have been attempts at independent replication of the Strange Stories test, showing that individuals with high-functioning autism and AS were impaired in their ability to answer questions requiring mind-reading abilities. Jolliffe and Baron-Cohen [20] used 18 of the 24 stories and also added a new control task. Heavey, Phillips, Baron-Cohen and Rutter [18] used six of the mentalistic stories and two of the control/ physical passages. In the present study the original stories were employed and for comparison purposes a new physical state control task was introduced. The aim of the present study was to assess whether relatively intelligent children and adolescents with AS would show any substantial impairment in social understanding when assessed on the Strange Stories test and whether they would pass the physical state control task. The prediction was that they would have more problems with the former than with the latter. A normally developing control group was included.All participants were tested on a standard first-order and a second-order false belief task.1 1 All participants passed standard false belief tasks, aside from one participant in the AS group, who failed a first order false belief task (the “Smarties task”) [32] and another participant in the same group, who did not pass a standard second order false belief task (the “Birthday-present task”) [38].
Method ■ Participants The stories were given to children and adolescents with AS (N = 21) with verbal intelligence within the normal range, and to a normally developing control group (N = 20). The participants in the AS group were recruited from Kasperskolen in Copenhagen – a special school for children and adolescents with Pervasive Developmental Disorders – and from the Centre for Autism in Copenhagen. They had been diagnosed independently in clinical settings according to the ICD-10 criteria for AS by experienced psychologists and child psychiatrists. The diagnosis of AS was only given when there was diagnostic agreement between the psychiatrists and the psychologists. In addition, the participants in the AS group had been assessed on ADI-R [28] and on ADOS [27]. The diagnosticians had no knowledge of the purpose or the design of the study. Thus, the selection of the participants was as stringent as possible, given the nosologically controversial diagnosis of AS.As males are over-represented [7] and females probably have a somewhat different clinical symptomatology from males [11], only the former were included in the current study. The controls participating in this study were volunteers recruited from different schools in Copenhagen.At the time of the study they had no known history of developmental lag or disorder. The two groups were matched on gender, age and parental socio-economic status (SES).The participants in the control group scored significantly higher on the WISC-III [42] and were slightly younger than the participants in the AS group. The importance of these group differences was analyzed in two ways: Firstly,the full groups analysis of covariance was conducted with verbal IQ and age as covariates (adjusting for full-scale IQ essentially showed the same results as adjusting for verbal IQ). Secondly, 13 AS index cases were individually matched to 13 control subjects on age and full-scale IQ; the matching was performed in such a way that the lowest functioning AS participants and the most intellectually able controls were excluded. Characteristics of the participants are shown in Table 1. The statistical analysis showed no significant age difference between the two groups (F[1,39] = 0.08, p < 0.78). All participants were within the normal IQ range (i. e.,VIQ > 85) when tested on the WISC-III. However, the control group performed significantly better than the clinical group on verbal IQ (F[1,39] = 11.48, p = 0.002), performance IQ (F[1,39] = 10.64, p < 0.002), and full-scale IQ (F[1,39] = 13.25, p < 0.001). Analysis of questionnaires, completed by the participants’ parents, revealed no significant group differences on level of parental education (F[1,38] = 0.02, p = 0.90), and parental occupational experience (F[1,38] = 1.22, p = 0.28). Two of the participants in the AS group were
N. Kaland et al. The Strange Stories test. A replication study of children and adolescents with Asperger syndrome Table 1 Participant characteristics: chronological age, verbal IQ, performance IQ, and full Scale IQ (mean, SD and range) Variable
Asperger group (N = 21)
Control group (N = 20)
F
p
CA Mean (SD) Range
15.86 (3.22) 10:2–20:4a
15.57 (3.28) 9:6–20:9
0.08
0.78
VIQ Mean (SD) Range
111.4 (16.92) 90–138
126.4 (10.57) 104–144
11.48
0.002
PIQ Mean (SD) Range
98.3 (14.36) 74–123
113.1 (14.71) 78–136
10.64
0.002
FSIQ Mean (SD) Range
106.4 (16.80) 81–134
122.7 (11.20) 102–142
13.52
0.001
a Years:Months
left-handed as opposed to four in the control group. All participants were free of medication at the time of testing.
■ Materials The tasks consisted of 24 short mentalistic stories and 13 physical control stories. The mentalistic stories – the Strange Stories test [15] – consisted of 24 short vignettes. There were two examples of each story type, comprising Pretence, Joke, Lie, White Lie, Misunderstanding, Persuasion, Appearance/Reality, Figure of Speech, Irony, Double Bluff, Contrary Emotions, and Forgetting. The mentalistic stories were accompanied by two, and for one story type, three test questions: the comprehension question, which usually took the form “Was it true, what X said?” and the justification question “Why did X say that?” The physical2 state control task [21] was presented in order to assess the understanding of physical events and check the generality of any comprehension deficit that might emerge irrespective of story content. The physical control stories had just one question, asking why a particular action had been carried out. Examples of the experimental stories are given in the Appendix.
■ Procedure The participants were tested in a quiet room in school or at the Centre for Autism. The stories were introduced as 2 The physical control task in the present study consisted of
a set of 13 stories, which were separated into a physical state and a mental state section. Only the physical state section was used as a control task.
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follows: Here are some stories, and some questions. I’m going to read the stories and I’d like you to listen carefully and then answer the questions at the end of each story.” The story was read to the participant – except in a few cases where the person preferred to read the story himself. The story remained in front of the participant throughout the session. At the end of the story the person was asked the test questions. The first question, “Was it true, what X said?” was a test of linguistic comprehension. If the answer was wrong the story was read out again until the person answered correctly or justified his answer. The answers to these questions were recorded but not further analyzed. The second question, the justification probe, “Why did X say that?” was then asked, and the participant’s answer was recorded in full (taped and written down on scoring sheets) for later analysis. Positive comments were made throughout the testing session to encourage the participant, but no feedback was given about the correctness of the answers. Administration was adjusted according to the requirement of each participant. Testing time varied from approximately 30–40 minutes to 1 hour. The participants used at least two, in some cases more, sessions to complete the test. Breaks with refreshments were given as needed. Prompt questions were given only if the participants provided no answers or inappropriate answers to the questions. For example, in the White Lie story a participant might be reminded that Peter did not like his aunt’s hat, by the additional prompt question “What did Peter think of the new hat?” (See story example in the Appendix). The participants in the control group received the stories largely in the same way as those in the AS group. The stories, translated into Danish, were intended to be unambiguous with only one explanation reasonably appropriate for the justification of why a particular action occurred. The stories were presented in random order, and two examples of one story type never followed each other.
■ Scoring The justifications were scored as either involving mental states or physical states. Mental state justifications included all those that referred to thoughts, feelings, desires, traits, and dispositions. They included terms such as like, want, happy, cross, afraid, know, think, joke, pretend, expect, lie, hurt, and to fool someone. Physical state justifications were those that referred to non-mental events, physical appearances, physical events, action of objects, and outcomes. They included terms such as big, looks like, is shaped like, get rid of, to sell, because of the X (object), to not get X (physical outcome), put in jail, told off, have a filling etc.).
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In accordance with the current scoring procedure for this task [17] participants’ answers to the justification question were scored as a 2 for a fully correct answer, 1 for a partially correct justification, and 0 for an incorrect justification. A correct justification was in most cases a mental state explanation. In some cases it could also be correctly answered with a physical state explanation. For example, in the Joke story where a boy calls a dog an elephant (see appendix), this could correctly be explained by the physical justification, “the dog is big like an elephant”,or by the mental state justification,“He’s just joking”. Similarly, an incorrect justification could be incorrect in two ways: in the physical sense, an answer that was contextually irrelevant, such as “the dog is not an elephant”and in the mental sense,“because the boy is lying”. A justification could be rated as incorrect because it involved errors about the facts given in the story, or because of an inference that was contextually inappropriate as a reason for the story character’s utterance. For example, in one of the Lie stories, in which a boy lies to his mother about his toothache because he does not want to go to the dentist, justifications like “He wants to tell his mother the truth” or “He is just joking” would be scored as incorrect because they include a factual error; in the context of this story it is not appropriate to interpret his utterance as telling the truth or joking. As responses sometimes turned out to be neither quite correct nor quite incorrect, they were rated as partially correct. For example, in one story an old lady misunderstands a stranger coming towards her, just wanting to ask her what time it is. She gives away her purse because she misunderstands his intention and fears that he will rob and hurt her. Answers to the “why” question such as “she did not know what he wanted” and the like were then scored as partially correct. The participants were scored according to their correct justification. That is, if a person provided one correct answer and one inappropriate answer, the correct answer was employed.Similarly,if a participant’s answer appealed both to a physical and a mental state, the justification was scored as a mental state.
■ Inter-scorer-reliability Two persons administered the stories, and subsequently one of these acted as a first rater. A third person, not being involved in the testing process, acted as a second rater. Judging whether an explanation on the justification question was appropriate or not is clearly subjective and made assessment of inter-scorer reliability necessary. In cases of disagreement, for example when the first rater considered the answer correct, whereas the second rater
considered the same answer partially correct, or incorrect, the mean of the two values was computed. For the physical control stories kappa was 0.76. For the mentalistic stories the degree of concordance was high, as only six justifications on the mentalistic test (out of 984 responses) received discordant ratings. Four of these were given by the participants in the AS group and two by those in the control group.
Results On the Strange Stories test the participants in the AS group answered the comprehension question (“Is it true . . .?”) essentially in a correct way. On rare occasions when a participant made an error, the story was read out again, until he answered correctly or justified his answer. On the “why” questions the participants in the AS group earned an average of 40.8 points on total correct/partially correct answers, whereas the control group received an average of 45. 1 points, out of 48 possible (Table 2). Comparison (ANOVA) showed a statistically significant difference between the groups on this task; a covariance-analysis with control for age and FSIQ showed that the difference was still statistically significant (p = 0.004) (cf. Table 2). When using a more strict coding procedure with fully correct versus partially correct/incorrect responses, there was a significant difference (ANOVA) between the groups (F[1,39] = 22.82, p < 0.0001); after control for age and FSIQ (F[1,37] = 10.91, p = 0.002). With the same coding procedure a paired t-test showed a statistically significant difference between the 13 AS index cases and the 13 matched control subjects (t[12] = 3.09, p = 0.009). When using the standard scoring procedure, outlined in the method section, there was still a significant difference between the groups on this measure (cf. Table 3). The participants in the AS group needed significantly more prompt questions than the controls in order to answer the justification questions on the Strange Stories – a mean of 6.5 as compared to the control group’s 0.8. The difference was statistically significant after control for age and FSIQ (cf. Table 2). On the physical control task the mean score of the participants in the AS group was 23.9 (out of 26 possible), as opposed to 24.8 in the control group. An analysis of variance (ANOVA) showed that the difference between the two groups was not statistically significant; control for age and FSIQ, however, yielded statistically significant differences between the two groups on this task (F[1,37] = 4.43, p < 0.05). When using a coding procedure with fully correct versus partially correct/incorrect responses the difference between the groups was not statistically significant when controlling for age and FSIQ (F[1,37] = 2.39, p = 0.13). A paired t-test showed no
N. Kaland et al. The Strange Stories test. A replication study of children and adolescents with Asperger syndrome Table 2 Results on the Strange Stories test and the Physical Control task – observed (SD) and adjusted means, F- and p-values
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Variable
Asperger group (N = 21) Mean (SD)
Control group (N = 20) Mean (SD)
F
p
Total score correct/partially correct justifications (max = 48): Observed mean (SD)a Adjusted meanb
40.76 (3.36) 41.49
45.08 (2.54) 44.31
21.33 9.34
< 0. 0001 0.004
Total number of mental state justifications: Observed mean (SD) Adjusted mean
20.14 (1.56) 20.36
21.15 (1.50) 21.02
4.45 1.67
0.04 0.20
Total number of physical state justifications: Observed mean (SD) Adjusted mean
3.86 (1.56) 3.64
2.85 (1.50) 2.98
4.45 1.67
0.04 0.20
Prompt questions: Observed mean (SD) Adjusted mean
6.52 (4.59) 6.41
0.75 (1.68) 0.89
28.04 19.48
< 0.0001 0.0001
Physical control task: Observed mean (SD) Adjusted mean
23.88 (1.72) 23.79
24.80 (1.36) 24.90
3.57 4.43
< 0.07 < 0.05
a Observed means: df = 1.39; b Adjusted means (results of covariance analysis): df = 1.37
Table 3 Results on the Strange Stories test when matching 13 pairs of participants in the Asperger and the control group on age and intelligence
Variable CA (months) VIQ PIQ FSIQ Performance, physical control task Performance, Strange Stories test Prompts, Strange Stories test
Asperger group Mean (SD)
Control group Mean (SD)
Difference
t
15.86 (2.67) 121.00 (13.70) 107.46 (9.09) 117.15 (11.08) 23.92 (1.32)b
15.91 (2.54) 123.62 (10.91) 108.08 (13.49) 118.92 (10.36) 24.69 (1.44)
–0.05 –2.62 –0.62 –1.77 –0.77
0.05a 1.10 0.23 1.77 1.33
0.96 0.29 0.82 0.10 0.21
41.92 (2.98)
44.65 (2.91)
–2.73
2.64
< 0.02
7.00 (4.73)
1.08 (2.02)
5.92
3.98
p
0.002
a df for paired t-test = 12; b Matching variables: Chronological age and full-scale IQ
significant differences between the 13 AS index cases and the 13 matched control subjects on the physical control task (t[12] = 1.33, p = 0.21, cf. Table 3). Further, the participants in the AS group did not need significantly more prompt questions than the controls on this task when using the standard scoring procedure [17], controlling for age and FSIQ (F[1,37] = 0.22, p = 0.64). The covariance analysis of total number of mental state justifications provided on the Strange Stories test showed that the participants in the AS group did not give significantly fewer such answers as compared to the participants in the control group (cf. Table 2). The analysis of the 13 matched pairs of participants also showed no significant difference between the groups on this variable (t[12] = 1.67, p = 0.12). As to correct mental state justifications the participants in the AS group performed less well than the par-
ticipants in the control group (p < 0.002). The AS participants provided, as one could expect, significantly more partially correct mental state justifications (= 0.005), but not significantly more incorrect mental state justifications than the participants in the control group (p < 0.36) (cf. Table 4). The relationship between participants’ performance on the Strange Stories test and verbal IQ, age and control task was examined. In the AS group there was a relatively strong correlation between performance on the Strange Stories test and verbal IQ (r = 0.60, p < 0.01). In the control group this association was weak (r = 0.19, ns). Performance on the Strange Stories test was significantly related to chronological age in the control group (r = 0.56, p 0.05), but not in the AS group (r = 0.18, ns). There was no significant correlation between performance on the Strange Stories test and the physical control
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Table 4 Number of correct, partially correct, and incorrect justifications – observed and adjusted means Variable
Asperger group (N = 21) Mean (SD)
Control group (N = 20) Mean (SD)
F
p
Correct mental state justifications: Observed mean (SD)a Adjusted meanb
15.48 (2.47) 15.89
19.00 (2.49) 18.57
20.23 10.67
< 0.0001 0.002
Correct physical state justifications: Observed mean (SD) Adjusted mean
2.62 (1.32) 2.74
2.20 (1.28) 2.07
1.06 2.01
0.31 0.16
Partially correct mental state justifications: Observed mean (SD) Adjusted mean
3.52 (1.57) 3.45
1.90 (1.07) 2.07
14.83 8.83
< 0.0001 0.005
Partially correct physical state justifications: Observed mean (SD) Adjusted mean
1.10 (1.04) 0.85
0.5 (0.89) 0.75
3.85 0.10
0.06 0.75
Incorrect mental state justifications: Observed mean (SD) Adjusted mean
1.00 (1.05) 0.8
0.35 (0.59) 0.6
5.91 0.84
0.02 0.36
Incorrect physical state justifications: Observed mean (SD) Adjusted mean
0.29 (0.46) 0.26
0.05 (0.22) 0.08
4.24 1.69
0.05 0.20
a Observed means: df = 1,39; b Adjusted means (results of covariance analysis): df = 1,37
task in either group: AS group (r = 0.17, ns) and control group (r = 14, ns). These findings should be treated with caution, however, given the small sample and the number of correlations computed. As shown in Table 5, the participants in the AS group provided more context-inappropriate mental state inferences, as compared to the participants in the control group. All participants in the AS group provided at least one such answer, 81% two or more, 57% three or more and 28% four or more context-inappropriate answers. This tendency was most apparent on the story types
Joke, Figure of Speech, and Irony. The participants in the control group provided relatively few such answers. As mentioned above, the stories were intended to be unambiguous, with only one explanation reasonably appropriate for the justification of why a particular action occurred. However, on the story type Forgetting quite a few participants in both groups provided alternative interpretations of the story persons’ utterances. As far as the answers provided on these stories could be a reasonable response to the justification question, they were scored as partially correct.
Table 5 Context-inappropriate mental state justifications on the Strange Stories – Asperger and control group
Discussion
Asperger group (N = 21)
Control group (N = 20)
Story type
Number
Percentage
Number
Percentage
Pretend Joke Lie White lie Figure of speech Misunderstanding Double bluff Irony Persuasion Contrary emotions Appearance/reality Forget
1 10 1 4 6 2 1 11 2 3 4 0
2.4 23.8 2.4 9.5 14.3 4.8 2.4 26.2 4.8 7.1 9.5 –
0 2 0 0 1 0 0 2 0 1 0 0
– 5.0 – – 2.5 – – 5.0 – 2.5 – –
The present results support the general experimental prediction: the theory of mind measures within the Strange Stories test paradigm revealed group differences, suggesting that relatively able individuals with AS have problems in interpreting simple stories about everyday events. The results on the mentalistic task were largely consistent with the finding of Happé [15] and Jolliffe and Baron-Cohen [20]. There was no statistically significant difference between the two groups on the physical control task when using a more strict scoring procedure and after the matching of the 13 AS and 13 control participants. This suggests that the current and more lenient scoring procedure for the Strange Stories test [17], described in the method section, may have slightly reduced the differences between the groups. The problems experienced by the participants in the clinical
N. Kaland et al. The Strange Stories test. A replication study of children and adolescents with Asperger syndrome
group were also evident in their need for more prompt questions than the controls when answering the mental state justifications, whereas they did not need significantly more prompt questions on the physical state control task. Although the participants in the AS group provided significantly less correct mental state justifications than the controls on the Strange Stories test, they did not yield significantly less total mental state justifications than the controls when differences in IQ between the groups were partialled out. This is in accordance with earlier findings [15, 20]. Several studies have shown that individuals with high-functioning autism or AS pass standard theory of mind tasks [e. g., 15, 21] – as was also the case in the present study. However, when more ‘advanced’ tests of theory of mind with a more complex social context were used, these individuals evidenced impairment in the area of social cognition [21]. In the clinical group there was also a relatively strong association between verbal IQ and performance on the Strange Stories test, suggesting that mentalizing deficits in individuals with AS are related to their intellectual competence [33]. Despite the covariance control analysis, an effect of IQ cannot be ruled out completely. However, when excluding the participants in the AS groups who obtained lower IQ scores than the lowest value of the control group, there was still a statistically significant group difference on the mentalistic task but not on the physical control task. This type of comparison yields more unambiguous results due to control of differential intellectual abilities. Although many of the participants in the AS group eventually provided correct, or partially correct justifications, often after one or more prompt questions, they often revealed idiosyncratic ways of interpreting everyday situations and tended to use mental state terms context-inappropriately. For example on the “why” question of one of the Figure of speech stories, where a girl coughs and coughs and her father says she must have a frog in her throat, one participant in the AS group answered that her father says it “. . because it’s much so, a sort of synonym or saying – as the destruction of Jerusalem”. Peculiarities were also found in one of the Joke stories where the story character says that the visitor’s big dog is an elephant. To the question of why they said this, several participants in the AS group stated the fact that the dog was not an elephant. But as one of them pointed out: “Exaggeration makes understanding easier”. Furthermore, to their more or less correct answers they tended to provide additional information of little relevance. The idiosyncratic and context-inadequate responses provided by the participants in the AS group, when still demonstrating some mentalizing abilities, could also be related to a weak drive for ‘central coherence’. This con-
79
cept refers to a tendency to process contextual information in a piecemeal fashion, as opposed to global processing [9]. Individuals with autism spectrum disorders are hypothesized to have a specific impairment in extracting meaning in context, and this tendency may partially explain the many context-inappropriate and peculiar responses provided by the participants in the AS group [15]. However, a weak drive for ‘central coherence’ should be distinguished from a failure to attribute mental states [16]. Another observation was that some of the participants in the AS group tended to give literal, physical interpretations of social events. Their difficulty in attributing context-appropriate mental states in the test situation seemed to make a physical explanation the preferred or easier option. Even when they recognized the difference between an imaginary representation and a real world situation they often emphasized this difference by saying “. . but in the real world it is not true”. Thus, the ‘cognitive style’, at least of the present participants, appeared to be more ‘physical’ than ‘mentalistic’. The story types Joke, Figure of Speech, Irony, and Contrary Emotions proved to be the most difficult ones for the participants in the AS group. However, some of the younger participants in the control group had also problems with these story types. Interestingly, many individuals in the clinical group performed relatively well on the double bluff stories, which require a third order theory of mind (i. e. an extra level of embedding), but less well on the irony stories, which also require a thirdorder theory of mind [14]. One possible explanation for this difference may be that the process of interpreting irony goes through other cognitive “routes” than working out an answer to a double bluff [3, 4, 6]. Hermelin and O’Connor [19], who invoked the concept of “logicoaffective” states, have argued that some individuals with autistic spectrum disorders are able to use cognitive mechanisms to deal with problems that are usually dealt with by affective processes. The use of cognitive rather than affective processes could also, as Bowler [3] suggests, result in a slowing of responses, and a disruption of the subtle timing of social interactions, thereby making the person seem odd to other people in social situations. Could memory or language problems represent the underlying cause of the AS persons’ difficulties on the Strange Stories test? In a recent study of high-functioning individuals with autism or AS, Bowler, Gardiner & Grice [5] found that their memory functions were relatively intact as compared with normally developing control persons. Matron, Morasses & Belleville [29] found no amnesic or semantic deficit in the memory of highfunctioning individuals with autism relative to normal controls. According to these studies it seems less likely that memory problems could have accounted for the im-
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paired mental state attribution found in individuals with AS in the present study. Although a receptive language problem cannot be ruled out, the difficulties experienced by the participants in the clinical group were probably not caused by lack of linguistic comprehension, since they did not evidence significantly more errors than the controls on the comprehension questions. Another finding that supports the view that a language problem can hardly be the cause of the difficulties experienced by the participants in the AS group is the fact that the groups did not perform differently on the physical control stories. As Sperber and Wilson [36] argue, language and communication are different and logically separate phenomena; language is a grammar-governed representational system and may be relatively intact in individuals with AS [14]. However, individuals with AS exhibit abnormalities in the social use of language [25, 34], which may primarily be related to their cognitive (theory of mind, executive functions) deficits [31, 39, 40]. Wing suggests that individuals with AS are generally slow in the test situation and that marks are lost on IQ tests because of their inability to work fast on timed items [45]. Some evidence for this view was found when the response times of the participants in the present study were recorded on another ‘advanced’ test of theory of mind, the Stories from Everyday Life [21]. The participants in the AS group were significantly slower than the normally developing persons in the control group, especially on mental state inference tasks [22]. The results of our use of the Strange Stories test suggest that the participants in the AS group showed significant impairment of social understanding, as compared to normally developing control persons. Conceptualized as a dimensional category and permitting considerable variation in personality [35], AS is arguably the most puzzling among the variants on the autistic spectrum. The combination of social ineptness and relatively good verbal ability remains one of the challenges to theories of social cognition. Future research, based on more refined tests and study design, should address this challenge.
Appendix
Story type: Joke Today James is going to Claire’s house for the first time. He is going over for tea, and he is looking forward to seeing Claire’s dog, which she talks about all time. James likes dogs very much. When James arrives at Claire’s house Claire runs to open the door, and her dog jumps up to greet James. Claire’s dog is huge; it’s almost as big as James! When James sees Claire’s huge dog he says, “Claire, you haven’t got a dog at all. You’ve got an elephant!” Is it true, what James says? Yes/No/Don’t know Why does he say this? Story type: White lie One day Aunt Jane came to visit Peter. Now Peter loves his aunt very much, but today she is wearing a new hat; a new hat, which Peter thinks is very ugly indeed. Peter thinks his aunt looks silly in it, and much nicer in her old hat. But when Aunt Jane asks Peter,“How do you like my new hat”, Peter says,“Oh, its very nice”. Was it true, what Peter said? Yes/No/Don’t know Why did he say it? Story type: Figure of Speech Emma has a cough. All through lunch she coughs and coughs. Father says: “Poor Emma, you must have a frog in your throat!” Is it true, what Father says to Emma? Yes/No/Don’t know Why does he say that? Story type: Irony Ann’s mother has spent a long time cooking Ann’s favourite meal; fish and chips. But when she brings it to Ann, she is watching TV, and she doesn’t even look up, or say thank you.Ann’s mother is cross and says, “Well, that’s very nice, isn’t it! That is what I call politeness!” Is it true what Ann’s mother says? Yes/No/Don’t know Why does Ann’s mother say this? Story Type: Misunderstanding Late one night old Mrs. Peabody is walking home. She doesn’t like walking alone in the dark because she is always afraid that someone will attack her and rob her. She is really very nervous! Suddenly, out of the shadow comes a man. He wants to ask Mrs. Peabody what time it is, so he walks towards her. When Mrs. Peabody sees the man coming towards her, she starts to tremble and says, “Take my purse, just don’t hurt me”.
■ Examples from the Strange Stories test:
Was the man surprised at what Mrs. Peabody said?
Story type: Pretend
Yes/No/Don’t know
Katie and Emma are playing in the house. Emma picks up a banana from the fruit bowl and holds it up to her ear. She says to Katie,“Look! This banana is a telephone!”
Why did she say that, when he only wanted to ask her the time?
Is it true what Emma says?
Yvonne is playing in the garden with her doll. She leaves her doll in the garden when her mother calls her to come in for lunch.While they are having lunch, it starts to rain. Yvonne’s mother asks Yvonne: “Did you leave your doll in the garden?”Yvonne answers:“No, I brought her in with me”.
Yes/No/Don’t know Why does Emma say this?
Story Type: Forgetting
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Lind, and says that she would like to have her piano tuned. She tells John her address. Some minutes previously a small job John was to do this morning in the concert house had been cancelled. A few minutes later he arrives at Mrs. Lind’s villa.
Is it true, what Yvonne says? Yes/No/Don’t know Why does Yvonne say this?
Question: Why doesn’t Mrs. Lind have to wait a week to have her piano tuned?
■ Physical control story examples The architect Ken Peterson is known as a person rich in ideas. He works with Solnes, a master builder who has his office in the town. He goes to Solnes almost daily with new ideas about how to build bigger and better buildings. The idea rich architect uses steel and glass as construction materials, because they are the materials that can give the most protection against storms and bad weather. With these materials it is possible to build fine, big buildings. Wooden material and roof tiles are well suited for the construction of normal single-floored dwellings, he says. Question: Why doesn’t architect Peterson use wooden material and roof tiles when projecting high buildings? John Frank is 25 years old and tunes all kinds of pianos. He is the only piano tuner in the town, and his clients must normally wait a week before he can do the work they desire. Usually he carries out his work in the homes of the clients. One day an old lady calls him. She presents herself as Mrs. Agnes
David Swenson is broke at the moment, because he has just paid some large bills. One day after filling his old, but well-maintained car with petrol he falls for the temptation of driving off without paying. The attendant at the station is busy with another customer, at the same time his telephone is ringing and a mechanic in the garage is calling him. Questions: Why doesn’t the serving attendant at the station stop Swenson when he drives away after not having paid for his petrol? One late, dark autumn evening the 14 year old Paul is going along some scary town streets with his mother. They have heard and read of people who have been robbed of their money in this area. Earlier that day Paul’s mother has been to the bank and made a withdrawal of 8000 NOK. She has placed the money in an inside coat pocket instead of in her handbag. Her old washing machine broke down for good a couple of days ago, and she has to buy a new one in one of the coming days. Question: Why has Paul’s mother been to the bank and made a withdrawal?
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