Behavioral genetics is a research field that studies the influence of heredity and environment on human behavior. By studying close relatives, behavioral geneticists are able to determine the effects of genes and environment on behavior.
Types of Behavioral Genetics Studies
Behavioral genetics studies use a variety of methods to study the effects of genes and environment. Adoption studies compare biologically related individuals with non-biologically related individuals, while twin studies look at how the behavior of identical and fraternal twins are similar or different. Behavioral geneticists also use family studies, which compare the behavioral characteristics of related individuals, and genomic studies, which use genetic information to look for correlations between genetic markers and behavior.
Examples of Behavioral Genetics Findings
Behavioral genetics studies have found that genes play an important role in determining behavior. For example, a number of studies have found that intelligence is heritable, with estimates of between 50-80% of individual differences in intelligence being influenced by genetic factors. Studies have also found that personality is heritable and can be linked to specific genes. For example, a study of more than 12,000 twins found that genetic factors played a substantial role in determining levels of extroversion.
The Role of Environment
Behavioral genetics studies also allow researchers to study the effects of environment on behavior. While biological and genetic factors may influence behavior, studies have shown that the environment plays an important role in determining behavior. For example, studies have found that individuals exposed to poverty and deep adversity are more likely to experience psychological and behavioral problems.
Studying close relatives allows behavioral geneticists to determine the relative contributions of heredity and environment to behavior. Behavioral genetics studies show that both genes and environment play important roles in determining behavior, and that neither factor is solely responsible. By understanding the contributions of both genetic and environmental factors, behavioral geneticists are able to gain a better understanding of individual behavior.