Answer:
‘‘He called these source traits’’
Explanation:
Raymond B. Catell (1905-1998) was an American psychologist of British origin, who researched on the basic dimensions of personality and temperament. He was a pioneer in the use of factor analytic methods in order to explore the basic dimensions of personality.
One of his main contributions was the discovery of sixteen separate trait factors, what he called ‘‘source traits’’, within the personality sphere.
Also, he conducted important research in other areas of psychology as intelligence and career assessment.