One of the main ways psychologists have studied the causes of differences in personality among people is to

A) perform factor analysis on answers given to written questionnaires about various traits.
B) ask people for their own explanations for how their personalities developed.
C) compare the similarities in personality between identical twins and fraternal twins.
D) unobtrusively observe people interacting in everyday situations.

Factor Analysis

A statistical method used to describe variability among observed, correlated variables in terms of a potentially lower number of unobserved variables, called factors.

Identical Twins

Siblings who are genetically identical, resulting from the splitting of a single fertilized egg.

Fraternal Twins

Twins who are born at the same time but developed from two separate eggs fertilized by separate sperm cells, resulting in them being genetically similar as siblings rather than identical.