Genes, environment and behavior 1. Genetic Influence on behavior A ...

Chapter Three: Genes, environment and behavior 1. Genetic Influence on behavior A. Gene manipulations and therapies - Epigenetics: changes is gene expression that are independent of the DNA itself and caused instead by environmental factors - Knockout procedure: altering a specific gene in a way that prevents it from carrying out its normal function (function is eliminated) e.g. preventing neurons from responding to particular neurotransmitter - Knock-in procedure: inserting a new gene into an animal during embryonic stage to study the impact on behavior after the animal is born B. Behavior genetics - Behavior genetics: Study how heredity, environmental and social factors influence psychological characteristics - Family studies: study relatives to determine if genetic similarity is related to similarity on a particular trait - Adoption study: adopted children are compared in some characteristic with their biological parents (shared genetics) and their adoptive parents (shared environment) o Intelligence, personality and psychological disorders have a notable genetic factor - Twin studies: comparison of trait similarities between fraternal and identical twins - Concordance rates: trait similarity - Heritability coefficient: estimates the extent to which the differences, or variation, in a specific phenotypic characteristic within a group of people can be attributed to differing genes. E.g. heritability for height ~ 80% (thus environment accounts for ~20% of height variation within groups) - Evolution = species adaption  learning = personal adaption 2. Adaption to the environment: role of learning A. Mechanisms and functions of learning - Behaviorism o Laws of learning that apply to virtually all organisms o Organism is tabula rasa ‘blank slate’  learning experiences inscribed on  environment thus dominates learning - Ethology o Species are biologically prepared to act in certain ways o Focused on the functions of behavior o Adaptive significance – how behavior influences an organisms chances of survival and reproduction in its natural environment o Fixed-action-pattern – an unlearned response automatically triggered by a particular stimulus (modifiable by experience e.g. gull chicks pecking parents red beak dot) B. Learning and evolution - Environment shapes behavior through species adaption and personal adaption 3. Behavior genetics; Intelligence and personality A. Genes, environment and intelligence