PSYCH 130 Lecture Notes - Lecture 3: Twin, Twin Study, Heritability
Document Summary
Wk 2, lec 3 - genetic and environmental influences. How to study contributions of genes and environment. The tendency of adoption agencies to place children in homes similar to those they were adopted from. Include pairs of siblings who have a variety of different degrees of genetic similarity: ex. identical twins, fraternal twins, biolgocial siblings, half siblings, unrelated stepsiblings who like together in stepfamilies, measire. Common experiences that work to make them similar. Ex. common parenting style, exposure to the same toys and peers: 3. Experiences unique to the individuals, not shared by others in family: correlations from a twin study, heritability of angry emotionality, average correlations between the iq scores of pairs of individuals. Intellectual abilities: heritability of iq scores is about . 50, genetic differences account for about 50% of the variation in iq, heritability of iq scores increases with age. During infancy both types of wins score similarly on the test of infant mental development.
