Behavior geneticists study the role of genetics in behavior by examining similarities in physical and behavioral characteristics of blood relatives, whose genes are more similar than those of unrelated individuals. They also perform reading experiments with laboratory animals. To see what aspects of behavior can be transmitted to an animal's offspring. Off course, genetic differences are only one of the causes of individual differences. People have different experiences, and these experiences will affect their behavior.
One of the major contributions of behavior genetics to the study of drug abuse has been the development of strains of laboratory animals that are especially susceptible to the effects of drugs. Comparisons of these animals with others who tend not to become addicted may help us understand the physiological mechanism involve in drug dependence.