What is the most common research method for answering the "nature-versus-nurture" question about the contributions of genetics and the environment to personality development?

A) a twin study
B) a friend study
C) a neighbor study
D) a large-scale questionnaire study

Twin Study

A study examining twins raised apart and together, usually to explore whether characteristics are caused by genetics or environment.

Nature-Versus-Nurture

A debate concerning the relative importance of an individual's innate qualities (nature) versus personal experiences (nurture) in determining or causing differences in physical and behavioral traits.