fects of traits on objective performance are moderated by cognitive factors
that are difficult to conceptualize in biological terms. Thus, the way is open
for a psychological account of traits, within which the neurological charac-
teristics of traits may be seen as partial or indirect influences on behavior,
rather than the sole basis for theory.
An Example: Extraversion–Introversion
We outline our cognitive-adaptive model initially with regard to extraver-
sion–introversion. A key observation is that traits are expressed behaviorally
through many qualitatively different kinds of criterion measure, representing
all three domains of the trilogy of mind. Furthermore, traits relate to criteria
abstracted to different degrees from the neural substrate, ranging from low-
level responses such as the startle reflex to high-level self-beliefs, cognitions,
and metacognitions with greater intellectual content (Matthews, Schwean, et
al., 2000). Figure 6.1 summarizes some illustrative correlates of extraversion-
introversion from this perspective: higher-level constructs are placed further
out in the pie. Thus, intellectual functions are located toward the periphery of
- TRAITS, STATES, AND INTELLECTUAL FUNCTIONING 147
FIG. 6.1. Examples of cognitive, emotional, and motivational correlates of
extraversion.