History of personality psychology

It is understandable that people from ancient times were interested in explaining individual differences in behavior.

the beginnings of personality theory date back to the times of the ancient Greeks. Hippocrates (460-370 BC), attempted to classify the major descriptors underlying individual differences in terms of four different types, which were a function of biological differences in fluids or the "four humours" — namely, the sanguine, choleric, phlegmatic, and melancholic temperaments.

According to the Greek physician Galen (130-200AD), who later reinterpreted Hippocrates' theory, differences in personality were a direct reflection of constitutional differences in the body.