What does family study typically investigate?

Family studies primarily focus on identifying genetic contributions to traits and behaviors by examining the similarities and differences among relatives. This method investigates how certain inherited characteristics or predispositions are expressed within families, looking at patterns such as how closely related individuals might share traits due to their shared genetic background.

The essence of family studies lies in understanding the heritability of specific traits by comparing members of the same family who share varying degrees of genetic relation, from parents to siblings to extended family members. By analyzing the traits that run in families, researchers can draw conclusions about the genetic basis of those traits and how they may be influenced by common ancestry.

In contrast, the other options focus on aspects that are less directly tied to genetics. For instance, the influence of siblings on behavior or the effectiveness of parenting styles pertain more to environmental factors, while the effects of upbringing on personality also emphasize environmental influences rather than genetic links, which are the central focus of family studies.