Nature vs. Nurture

Behavior Genetics The study of the influences of heredity and the environment on behavior “Nature” vs. “Nurture” Environmental influences (everything non-genetic) Our genetic influences – inborn traits

What makes someone… A superior athlete?

What makes someone… Funny?

What makes someone… Mean, cruel, or evil?

What makes someone… Intelligent?

What makes someone… Brave?

What makes someone… Shy? or outgoing?

Is it “nature” or “nurture” ?

Adoption Studies ? ? Is the child more like the biological parents (“nature”) or adoptive parents (“nurture”)?

Twin Studies Can compare identical twins with fraternal twins Monozygotic = identical twins (one egg, exact same genetics) Dizygotic = fraternal twins (two eggs, no more genetically similar than other siblings)

Twin Studies Can study identical twins separated at birth Same “nature” … different “nurture”

Minnesota Twin Studies Dr. Thomas Bouchard & Dr. David Lykken Conducted famous longitudinal studies on twins at U of M to attempt to determine which characteristics we inherit (nature) and which we acquire (nurture) Included 8,000 pairs of twins born b/w 1936-1955 Hypothesis: Even if identical twins were reared apart, they should exhibit the same traits in many areas due to the fact that they share 100% of genetic blueprint. Those traits that differed were due to environmental influences.

Bouchard’s findings Heredity played a greater role than environment in determining personality traits Environmental factors still play a small role Identical twins reared apart are as similar as identical twins reared together and are more similar than fraternal twins

Research Research nature v. nurture studies to support or refute the following statement related to the debate; “Parenting is the number one influence on a child’s success or failure and happiness or unhappiness in life. “ Present your conclusion in a 10 slide report with evidence to support your conclusion.