Personality and intelligence

In any discussion of personality and intelligence, it must be acknowledged that the traditional conditions for assessment of these two domains are quite different. On the one hand, as Cronbach (1949) noted, personality traits are assessed by asking an individual how he or she ‘typically’ behaves; that is, to assess a personality trait like Extroversion, the individual might be asked to agree or disagree with a statement like ‘I enjoy going to parties’. In other words, the traditional goal of personality assessment is to determine how an individual would behave when there is little or no environmental press on his/her behaviour (i.e., weak situations). Part of the rationale that underlies this approach is that the variability in behaviour across different individuals is expected to be much more restricted when the environmental press or situation is a strong one. For example, if a group of randomly-selected individuals were each offered US $1,000,000 (a strong environmental press) to jump out of an airplane with a parachute (and a spare), one might reasonably predict that a substantial majority of the group would ‘jump’ at the opportunity. In contrast, if the same group of individuals were simply offered the chance to skydive without any monetary incentive (a weak environmental press), one might reasonably predict that there would be relatively few individuals who agree to jump, and furthermore, that an assessment of personality characteristics such as thrill-seeking might provide a good prediction of which individuals are more or less likely to jump. Therefore, the domain for personality is perhaps best thought of as a tendency to behave in a certain way, especially when there is only a weak environmental press. Intellectual abilities, on the other hand, are traditionally assessed under ‘maximal’ performance conditions; that is, the individual being assessed is not asked to complete an ability test as if there were no environmental press. In fact, the key concept to most modern ability assessments is that the individual needs to either internalize or be provided with explicit instructions to treat the test as if performing well was a highly valued goal (Ackerman 1996). In selection contexts (whether for occupational or educational purposes), where the goal is to get the job or to be admitted into a desirable school, the environmental press for maximal performance is very strong — indeed, in some cases, the test situation may lead to anxiety or subjective distress because the press is so strong that it may distract the individual from performing his/her best. Ultimately the goal of ability assessment is not to determine how the individual behaves when there is no environmental press, but rather determine the limits of the individual’s performance if he/she is trying as hard as possible to succeed. This difference between the traditional approaches to personality and intelligence assessments sets the stage for a mismatch of constructs, in a manner that would be expected to minimize the associations between the two constructs (see e.g., Wittmann and Süß 1999). However, there is no inherent reason why one cannot consider personality in a maximal performance context, such as when one asks whether individuals are capable of public speaking, regardless of whether they might prefer staying home with a cold compress over the eyes to getting up to talk in front of a large group of people (e.g., see Wallace 1966; Willerman, Turner and Peterson 1976). Similarly, intelligence can be considered in a typical behaviour context (see e.g., Ackerman 1994 for a discussion of this issue). In later discussion, a construct of ‘typical intellectual engagement’ will be discussed in some detail.