Genes, environment, and behavior
How do genes influence who you are and what you do?
- increase the size of their fat cells or dictate how they use fat in their body
- release chemicals (like hormones) which control hunger and appetite
- influence behavior as Jennifer and Karen interact with their environment. For example, if Karen begins to gain weight, she may seek out fewer opportunities to exercise because going to the gym makes her feel uncomfortable.
How do your life experiences influence your genes?
Is there a way to tell how much of an influence genes have on a behavior?
Consider the following:
- Why do you think heritability estimates cannot be generalized, or applied to different populations? Consider exactly what a heritability estimate measures - the relative influence of genes and the environment. If there was a change in the environment, the heritability estimate would change as well; an estimate from Jennifer’s neighborhood would not be applicable in Karen’s neighborhood. Each estimate is very specific to one group of individuals and their environment, which means that it could not be generalized. However, we can look at large groups of people and develop a range of estimates to tell us more about a particular trait of interest. The range allows for interpersonal and small group differences that are influenced by specific environments, but still gives us important information about the differences in people’s traits.
- The interactions between your genes and your environment are especially important during your early development. For example, exposure to toxins during and immediately after pregnancy can produce lasting effects on a baby’s health - children exposed to pesticides at a young age have a higher risk of developing mental health problems later in life.