Answer:
Personality psychology
Step-by-step explanation:
Personality psychology is used to test for individual differences such as behavior patterns,social attitudes,traits etc; it shows personality and its variation among individuals which shows that there is self-concept in all being. Gordon Allpor is considered as the father of Personality psychology.
This branch of psychology helps researchers compare the traits of their subjects to psychological force.Therefore,Personality psychology is the specialty area that best represent Dr. Roberts validation of tests to assess individual differences in traits.