UNIT 3 BIOLOGYMod. 14: Behavior Genetics—Predicting Individual Differences

Genes: Our Code for Life

• Behavior Geneticists: study human differences and weigh the effects and interplay of heredity and environment• Environment—external influences• Genetics: human life…a book with 46 chapters (chromosomes), 23 from each parent• DNA: genetic info , makes up chromosome• Genes : tiny units of DNA, 20,000-25,000

• If active, they are expressed

Genes Cont.

•Genome: instructions for creating an organism• Gene sequencing

•Geneticists study gene variations and how it affects behavior/though/ etc

•Genetic predisposition: genetically influenced traits help explain both shared human nature and diversity

Twin and Adoption Studies

• Identical Twins (monozygotic)•Fraternal Twins (dizgotic)

• Identical twins are basically a clone, same genes with some slight variations

Separated Twins

• “Jim” twins…example from your book• Critics will say while they were separated they were probably raised in similar setting and looking for similarities

Biological vs. Adoptive Relatives

•Adopted children are more like their birth parents in regards to personality

•Adoptive parents influence attitudes, values, manners, faith, and politics

Molecular Genetics

•Focusing on specific genes that affect behavior• Genes interacting • Looking for risks of disease

Heritability• The proportion of variation among individuals that we

can attribute to genes• Varies, depending on populations and environments

being studied• Measured from 0-1:

• 0 [0%] (low heritability): Influenced by environment• 1 [100%] (high heritability): Influenced by genes

• E.g.: If the heritability of intelligence in a given population/environment is 40% (moderately low), then genetic influence explains 40% of differences in intelligence among that specific population

• Herit: Inherit• Ability: Capability

Genes—Environmental Interaction

•Our genes and environment interact•Epigenetics: studying gene-environment interaction