Why do people enlist in the U.S. military? It’s genetic:
Analysis of twin pairs drawn from the National Longitudinal Study of Adolescent to Adult Health (Add Health) revealed that 82% of the variance was the result of genetic factors, 18% of the variance was the result of nonshared environmental factors, and none of the variance was accounted for by shared environmental factors.
Every aspect of every organism has a genetic component, and that includes all human behaviors.
A. It is a family tradition.
B. Get away from mama and do something on your own for the first time.
Don’t twin studies account for stuff like family tradition?