Validation work on the Big-Five and the Five-factor Model

2.2.2 Validation work on the Big-Five and the FFM

Research conducted to validate the FFM has generally returned findings that support the existence of five major personality factors. Conley (1985) found stability over time and method for four personality traits of the FFM (Culture/Openness to Experience was excluded from analyses). Conley noted that simply asking participants to repeatedly complete the same self-report over time could result in high test-retest correlations due to a consistent self-perception, rather than personality per se. To avoid this potential error, Conley used ratings from self, marriage partner and acquaintances in his research. Similarly, Soldz and Vaillant (1999) found the five factors to be stable over a forty-five year period beginning in young adulthood. In addition to this, the five factors and their facets have been found to be partly heritable (Jang et al., 1998; Loehlin, McCrae, Costa, & John, 1998), and as Buss (1996) pointed out, they probably had adaptive value in a prehistoric environment. In particular, Riemann, Angleitner and Strelau (1997) studied German twin pairs (660 monozygotic, 200 same sex and 100 opposite sex dizygotic) aged 14-80 and found through self- and peer-reports on the NEO Five-Factor Inventory (NEO-FFI) items that genetics had a substantial influence on the five factors. Saudino et al. (1999) using a different questionnaire and a smaller sample size in Russia, with a mean age of 42.23 years, also concluded that personality traits (neuroticism, extraversion, monotony avoidance, and impulsivity) were inherited and that the factors influencing individual differences in personality in Russia were not far removed from those that influence personality in more Western countries.

These and similar findings have led writers such as Digman and Inouye (1986) to confidently conclude “…a series of research studies using personality traits has led to a finding consistent enough to approach the status of a law…If a large number of rating scales is used and if the scope of the scales is very broad, the domain of personality descriptors is almost completely accounted for by five robust factors” (p.116). Digman and Inouye (1986) also make the point that Mischel (1968) had a less than favourable attitude toward the trait movement, but subsequently reported substantial correlations between trait ratings and objective indices of traits (Michel, 1984). Further Big-Five/FFM validation work that is more specifically related to criterion-related validity appears in Section 2.8.