What are the disadvantages of using twins studies?

Answer 1

First off, twins are hard to come by.

This is especially true of conditions that are already rare, since they do not often have the chance to conduct a twin study due to the low probability of finding an already rare condition in twins.

Twin studies are more likely to be case studies, which limit their scope and generalizability.

If the twins were raised together, the assumption that similarity in twins is the result of heredity has to compete with the explanation that some similarity is attributable to a common upbringing and not genes alone.

Answer 2

Some disadvantages of using twin studies include potential difficulty in determining the unique contributions of genetics and environment, limited generalizability to the broader population, and ethical concerns related to the use of human subjects, especially in cases of separation of twins.