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Evolution and Genes


Table of Contents

Principles of Genetics

Which has the greater effect on human behavior: nature or nurture? Hair color, height, and many other physical characteristics depend on genes, or nature, but the origin of behavior, intelligence, and personality is not so clear. Most scientists agree that both genes and the environment play a role in behavioral development, but disputes still rage over the degree of influence exerted by each.

A branch of psychology known as behavior genetics examines the genetic base of behavioral and personality differences among people. Behavior genetics is a controversial field, since misuse of psychological research into the genetic roots of behavior can have horrifying results. Several generations ago, psychologists and other scientists used arguments about the genetic influence on behavior and intelligence to support racist theories about the superiority of Anglo Americans. Moreover, these theories often became the foundation of public policies that discriminated against African Americans and Native Americans. Today, behavior geneticists carefully consider the potential political repercussions of their work.