ferences accounted for some, but not all, of the gender differences in domain
knowledge—where women tend to perform more poorly overall (for an ex-
tensive discussion of this issue, see Ackerman, 2002; Ackerman et al., 2001).
Results from other studies have been consistent with these findings (e.g., see
Rolfhus & Ackerman, 1999), and have extended the investigation to include
domain knowledge in current events (Beier & Ackerman, 2001) and health
and nutrition (Beier & Ackerman, 2003). However, in the current events do-
main knowledge, few gender differences were noted, and in the health and
nutrition knowledge domains, women outperformed men on average. To-
gether, these results show the efficacy of the PPIK approach for the trait
complex determinants of individual differences in domain knowledge—
which represent an important component of typical performance on intellec-
tual tasks.
CHALLENGES AND FUTURE RESEARCH
The chapter has focused mainly on typical behavior and maximal perform-
ance, but it should be clear that these are extreme endpoints of a single con-
tinuum. Many different variables are certain to influence the level of effort
put forth, both across individuals, but also within-individuals. In some ways
this issue is similar to the underlying trait versus situation debate that con-
fronted personality theorists in the 1960s and 1970s (e.g., see Mischel, 1968).
Mischel initially argued that personality traits were largely unpredictive of
behaviors, whereas behavior was largely determined by situations instead.
The major source of resolution to the controversy was the notion of aggrega-
tion of behavior—that is, when multiple behaviors are observed across many
situations, the influence of personality traits in predicting behavior was much
greater.
Environmental Press or Situations
The aggregation issue is not only central to the trait versus situation contro-
versy, it is an integral aspect of the typical behavior perspective described
here. Thus, an appreciation of the situation, or more precisely, the level of en-
vironmental press, will be an important component of future progress in this
area. Numerous investigations of motivational interventions, such as the ex-
tensive literature on goal setting (e.g., see Kanfer, 1991, for a review), provide
some insight into the determinants of effort allocations. Nonetheless, there is
not a taxonomy of situations that can predict how much effort will be ex-
pended under a particular environmental press. Ironically, the elicitation of
effort under aptitude and intelligence testing conditions is probably one of
the few situations that psychologists and educators use (or even could use)
- TYPICAL AND MAXIMAL PERFORMANCE 135