Answer:
The answer is: Adoption study
Step-by-step explanation:
Adoption study estimates the degree of variation in human traits caused by the genetics or environmental influences. This method is used to investigate the similarities in the genetics of the adoptive and the biological parents.
It is a tool of behavioral genetics. Heritable genetic effect refers to the resemblance with the biological parents. Whereas, shared environmental effect refers to the resemblance with the adoptive parents.