Cognitive ability and interests reciprocally influence each other such that people tend to become more interested in what they are good at or what they think they are good at (e.g., Barak, 1981; Tracey, 2002). Although self-rated abilities are significantly correlated with actual abilities, the relationship is not strong (Mabe & West, 1982). As such, beliefs influence the development of interests in two ways: first, beliefs about need fulfillment influence initial interest development (for example, the belief that being around other people when one is working can help satisfy the need to belong and may influence the development of social interests); second, beliefs about one’s own abilities influence subsequent interest development (e.g., Savickas, 1999).
Personality may also influence the development of abilities, skills, and knowledge in several ways. First, those who are highly conscientious put more effort into learning and thus develop more abilities, skills, and knowledge. Again, we would predict that the decision of where to invest one’s effort would be determined by interests. Second, those who are introverted tend to develop more knowledge than those who are extraverted (e.g., Matthews, 1997; Schmidt, 2014). Third, some personality traits may guide the investment of cognitive ability (von Stumm & Ackerman, 2012). Traits such as openness and typical intellectual engagement (TIE) “capture individual differences in the desire to comprehend and engage in intellectual problems” (von Stumm & Ackerman, 2012, p. 843). Such traits have also been shown to be positively correlated with acquired knowledge (von Stumm & Ackerman, 2012). Interestingly for the purposes of the current discussion, whereas von Stumm and Ackerman refer to TIE as a personality dimension, Schmidt (2014) refers to TIE as simply a very broad form of interests (an interest in learning about many things).
Research suggests that personality change can result from changes in roles, expectations, and demands. Similar to the investment of abilities, social investment is defined as “investment in, and commitment to, adult social roles” (Lodi-Smith & Roberts, 2007, p. 68). Clearly, personality, interests, and cognitive ability are major determinants of at least one’s work role. People tend to choose occupations they feel fit their personality and interests, and their choices are constrained by their levels of academic and cross-cutting cognitive skills. According to neo-socioanalytic theory (Roberts & Wood, 2006), investment in work roles should lead to changes in personality traits. As one’s role changes, it is likely to impact one’s identity (how one views him- or herself) and reputation (how one is viewed by others), which can then influence personality. For example, the transition from college to the workforce would influence one’s identity and reputation. Consistent with this prediction, one meta-analysis found that work investment is related to changes in conscientiousness, agreeableness, and emotional stability (Lodi-Smith & Roberts, 2007).
Theoretical Functional Differences
The notion of investment (both ability and social investment) suggests that cognitive ability, personality, and interests function differently but collectively facilitate the navigation of education and career decisions. Cognitive ability is a major determinant of what one knows and is able to do. More specifically, it may represent an upper limit on how much one is ultimately able to know and do. Academic skills, as reflected in the concept of crystallized intelligence, can be considered a subset of cognitive ability. Personality, at least its behavioral components, is what one actually does. In a broad sense, it also partially serves to motivate general behavior. For example, a conscientious person will be motivated to work hard in general, and a person who is high in openness will be motivated to learn facts in general. Interests serve to determine specific activities surrounding what one is willing and/or prefers to do. They direct attention to particular activities and partially determine the intensity with which one engages in those activities (Rounds & Su, 2014). Whereas conscientious people may be motivated to work hard in general, a person with investigative interests will be motivated to work hard in specific investigative tasks. To be sure, these are oversimplifications of the functions of these three broad constructs. However, given the state of research and theory on the interaction of these three areas, such a simplification represents a solid starting point in furthering our investigation.