Identify three approaches that are used to identify whether a trait or disorder has a genetic component. In your opinion, which approach is the most effective for sorting out the contributions of nature versus nurture, and why?

Question

What will be an ideal response?

Answer 1

Correlational approaches to examining genetic contributions to traits or disorders include family studies, adoption studies, and twin studies. Genetic engineering methods for causally linking a gene and a trait or disorder include knockouts, antisense RNA, and gene therapy. The correlational methods can be safely used to study preexisting genetic differences in humans, but these approaches all have potential extraneous variables that cannot be controlled for. Family studies have the most potential for confounds because members of the same family also share much of the same environment as each other. Adoption studies and twin studies have less potential for confounds than family studies, although there can still be confounds. Adopted families will share fewer similarities than biological families, but people tend to adopt children from backgrounds that are similar to their own. While identical twins share 100% of their genes, they also tend to share more of their environment than fraternal twins do, in part because of more shared prenatal environment and in part because looking similar can elicit more similar reactions from the environment than siblings who look different. Genetic engineering methods are better able to causally link one or more genes with a trait, because researchers manipulate genes and then measure traits or disorder risk. However, these techniques cannot be ethically performed in humans for research purposes and pose potential risks such as causing unintended side effects.