PSY 301 1st Edition Lecture 8 Outline of Last Lecture I Monoamines II Neuromodulators III Corpus Callosum IV Behavior Genetics Outline of Current Lecture I Twin Studies II Adoption Studies III Effects of genes environment Current Lecture Twin Studies Twin studies help us understand what characteristics are determined by our genes and what is influenced by our environment Identical twins monozygotic help us better understand our genetic influence o Share 100 of their genes Fraternal twins dizygotic help us understand how our environment impacts us o Share 50 of their genes o Share the same amount of genes as any brother or sister would o Only difference between fraternal twins and siblings is the age difference o Fraternal twins help us understand the difference in age between siblings and how this affects our characteristics and upbringing If a characteristic is very influenced by genetics then monozygotic twins should be more similar in that characteristic than dizygotic twins If a characteristic is very influenced by the environment then monozygotic twins should be no more similar in that characteristic than dizygotic twins If a characteristic is very influenced by the environment then dizygotic twins should be more similar in that characteristic than non twin siblings Adoption Studies Used to compare adopted children to their biological and adoptive families o Example When a poor family gives up a child for adoption and that child is adopted by a more affluent family that adopted child tends to show more potential than his her biological siblings because the affluent family is able to provide more to this child nutrition education etc If a characteristic is very influenced by genetics then adopted children should be more like their biological parents than their adoptive parents in that characteristic If a characteristic is very influenced by the environment then adopted children should be more like their adoptive parents than their biological parents in that characteristic Effects of Genes and the Environment Interact Genes and environment are part of a single system influencing behavior Genes can influence traits which affect responses and environment can affect gene activity a Passive interaction what a child passively receives from genes and environment b Evocative reactive interaction reactions of the world to a person based on that person s characteristics c Active interaction when a person chooses aspects of their environment based on their characteristics Reaction range the inherited range for a characteristic Set point the final value of the characteristic which is set by the environment
View Full Document
Unlocking...