Genetic similarity is referred to as relatedness. The greater the genetic similarities between two individuals or a group of individuals the higher the degree of relatedness.
An awareness of the degree of relatedness between MZ and DZ twins, siblings, parents and children, and parents and adopted children provides a critical perspective in evaluating twin or kinship studies.
- Twin study: Kendler et al. (2006)
- Family Study:
- Adoption Study:
SAQ: With reference to one example, explain how genetic similarities help psychologists to understand the link between genes and behaviour. (9)
ERQ: To what extent can research into genetic similarities explain the link between genes and behaviour. (22)