To+what+extent+does+genetic+inheritance+influence+behavior?

Carolina Vargas __Minnesota Twin Study (Bouchard, 1990)__ __Scarr and Weinberg (1977)__ __Christiansen (1977)__
 * __To what extent does genetic inheritance influence behavior?__**
 * Genes influence all behavior, but genes are not responsible for any behavior.
 * Having a gene that is linked to a certain behavior does not mean that behavior will be exhibited, because not all genes are expressed.
 * **Behavioral genetics** is the study of how both genetics and the environment influence individual variations in human behavior
 * Behavior is a bidirectional process, meaning that genes and the environment both influence each other to affect our behavior.
 * Our behavior is also not caused by a single gene, as this is a **reductionist** approach. As both one’s genes and one’s environment affect their behavior, genetic inheritance only influences behavior to an extent.
 * Longitudinal study of twins in Minnesota, meaning that research of twins has conducted over a long period of time: since 1979
 * Participants were interviewed about their personalities, environments and academic ability.
 * Monozygotic or identical twins that were raised apart were compared to monozygotic twins raised together.
 * Bouchard found that both twins reared together or apart had a relatively equal chance of having similar personalities, interests and attitudes.
 * This demonstrates that the similarities between twins are genetic, because twins reared apart are exposed to different environments, but are just as likely to have similar personalities to their co-twin.
 * He also estimates that there is a 70% heritability of intelligence, with 30% coming from other environmental factors.
 * However, this study assumes that twins reared together were exposed to the same environment.
 * Racial adoption study in which IQ scores of interracial children adopted by advantaged white families were compared to biological children.
 * They found that the biological parents’ educational levels were better predictors of the adopted children’s IQ scores than were the IQs of the children’s adoptive parents.
 * This supports Bouchard’s findings that intelligence is highly heritable, and is influenced greatly by genetics.
 * Studied sets of Danish twins for criminality and aggression to see if there are biological factors that contribute to criminality.
 * He found that there is a concordance rate of 35% between identical male twins and 13% in fraternal male twins, and 21% for identical female twins, and 8% in fraternal female twins.
 * This suggests that there are genetic factors involved in criminal behavior, but are mostly due to other environmental factors, because they are not very high percentages

This shows that genes are an important factor in determining behavior, but are not the entire answer. Genetic inheritance influences behavior to some extent, but the expression of a gene depends on its interaction with environmental factors and other genes.