What is the purpose of a family study in genetics?

The purpose of a family study in genetics is to examine traits and behaviors among relatives. This approach allows researchers to observe patterns of inheritance and the heritability of certain traits by studying how these traits manifest in family members. By analyzing data across generations, geneticists can identify the likelihood of traits being passed down, as well as the influence of genetic factors in relation to environmental influences. Family studies are particularly useful for understanding complex behaviors and conditions that may have both genetic and environmental components.

The other options do not accurately capture the specific focus of family studies. Comparing genetic traits between unrelated individuals does not provide insight into heritability within a family context, while analyzing genetic differences between twins looks at specific genetic frameworks rather than broader family dynamics. Investigating environmental effects on genetics focuses more on external factors rather than the familial relationships that are central to a family study.