Behavioral genetics of the higher-order factors of the Big Five

There is empirical evidence that underlying the Big Five personality factors are two higher-order factors which have come to be known as "alpha" (α) and "beta" (β). The α factor is defined by the agreeableness, conscientiousness, and emotional stability domains; whereas β is delineated by extraversion and intellect. It has been argued that α and β are important constructs because they bridge the gap between psychometric studies of personality and theories of personality development. However, it is unclear if α and β are constructs that can be reliably reproduced across a diverse range of independent samples. In a sample of 1209 MZ and 701 DZ twin pairs from Canada, Germany, and Japan who completed the NEO-PI-R, factorial analyses of the five NEO-PI-R domains extracted two factors resembling α and β. Subsequent multivariate genetic analyses revealed that this factor structure was a clear reflection of the organizing effects of multiple genetic influences, providing evidence for α and β as stable heuristic devices that can be used to integrate personality measurement and developmental theory.