Extensive research has been done on personality and many researchers have agreed that personality is best conceptualized as a five-factor model (the Big Five).

This resulted in a five-factor model consisting of altruism, courtesy, conscientiousness, sportsmanship, and civic virtue.

Validation of the five-factor model across instruments and observers.

Personality disorders and the five-factor model of personality (2nd ed.)

A socioanalytic perspective on the five-factor model.

In personality psychology, researchers have generally agreed on a five-factor model of personality.

A broad-bandwidth, public domain, personality inventory measuring the lower-level facets of several five-factor models.

"An introduction to the five-factor model and its applications" (PDF).

The intercultural factor analysis yielded a close approximation to the five-factor model and the factor scores were meaningfully related to other cultural level variables.

It also integrated several items that did not fit well with the five-factor model and provided further evidence for the idea of reciprocal and kin altruism.