Chapter 1. Behavior Genetics

Short Description

Decades of research in the area of behavior genetics suggest that both genes and environment play an important role in determining individual differences in human behavior.

Long Description

Information stored in our DNA influences not only our hair color or height, but also our intelligence, temperament, and predisposition to psychological disorders. But, what do we get from our environment? This program explores the delicate relationship between nature and nurture, and ethical implications of genetic testing and manipulation.

Twin studies that compare identical and fraternal twins are valuable tools used by behavioral geneticists because of the genetic and environmental similarities that exist between them. The narrator cites a study conducted by University of Minnesota researcher Thomas Bouchard on identical twins raised apart in different environments. Despite the environmental differences, the twins proved to be more alike than not in terms of personality traits, intelligence, and interests. Similarly, results from adoption studies indicate the power of genes over environment.

Scientists have been able to use statistical analyses to estimate the heritability of particular traits. Therefore, the study of heritability reveals how much variation among individuals is due to genetics, the environment, and the interaction of the two. In recent years, technology has allowed scientists to study genetics on a molecular level and pinpoint precisely which genes are responsible for predisposing us to certain outcomes such as bipolar disorder, schizophrenia, and substance abuse. Michael Lyons, however, raises this important question: If given the opportunity to reduce risk and select favorable traits in your offspring, would you?

Questions