family study
research conducted among siblings, parents, or children to assess evidence for genetic links for characteristics or outcomes, often related to health or disease. For example, a family study might be conducted to assess whether individuals from the same family who share a similar genetic structure also have similar responses to a health-promotion intervention such as diet, exercise, or medication. The extent to which performance on a given measure varies as a function of genetic similarity is used as an indication of the heritability of that measure.