In press, Developmental Psychology Personality-Cognition Relations across Adulthood

Although an increasing number of studies have investigated relations between dimensions of personality and level of cognitive functioning, the research results have been somewhat inconsistent. Furthermore, relatively little is known about whether the personality-cognition relations vary as a function of age in adulthood. The current project examined these issues with data from a sample of 2,317 adults between 18 and 96 years of age who each completed a personality inventory and performed a broad battery of cognitive tests. The results revealed strong relations of the personality trait of Openness with several distinct cognitive abilities, and smaller relations of other personality traits with specific cognitive abilities. Comparisons across different age groups indicated that the personality-cognition relations were both qualitatively and quantitatively similar across the adult years. Personality-Cognition Relations 3 There has been considerable research on the relations of age to personality (e.g., McCrae, Martin & Costa, 2005; Roberts & Mroczek, 2008; Srivastava, John, Gosling & Potter, 2003; Terracciano, McCrae, Brant & Costa, 2005), on the relations of age to cognition (e.g., Salthouse, 2004; Salthouse & Ferrer-Caja, 2003; see Craik & Salthouse, 2008 for a review), and some research on the relations of personality to cognition (e.g., Ackerman & Heggestad, 1997; Moutafi, Furnham & Crump, 2006; Schaie, Willis & Caskie, 2004). However, results of studies investigating personality-cognition relations have not always been consistent. For example, reported correlations between both Extraversion and Conscientiousness have sometimes been positive and sometimes negative (for contradictory results on Extraversion: e.g., Ackerman & Heggestad, 1997; Austin et al. 2002; Meier, Perrig-Chiello, & Pierrig, 2002; Moutafi, Furnham, & Paltiel, 2005; Moutafi, et al., 2006; see also Wolf & Ackerman, 2005; for contradictory results on Conscientiousness: e.g., Allik & Realo, 1997; Booth, Schinka, Brown, Mortimer, & Borenstein, 2006; Furnham & Chamorro-Premuzic, 2006; Moutafi et al., 2006; Moutafi, Furnham & Crump, 2003; Moutafi, Furham & Paltiel, 2004). In addition, although the relations of Neuroticism to cognitive measures tend to be negative in nature (e.g., Crowe, Andel, Pedersen, Fratiglioni, & Gatz, 2006; Judge, Higgins, Thoresen, & Barrick, 1999; Wilson, Schneider, Boyle, Arnold, Tang & Bennett, 2007), they have not always been significant (e.g., Arbuckle, Gold, Andres, Schartzman, Chaikelson, 1992; Hultsch, Hertzog, Small & Dixon, 1999; Jelicic, Bosma, Ponds, Van Boxtel, Houx, & Jolles, 2003; Schaie et al., 2004; Wheterell, Reynolds, Gatz & Petersen, 2002). The most consistent finding regarding the relations between personality and cognition may be that higher levels of Openness are associated with better performance on several cognitive Personality-Cognition Relations 4 tasks (e.g, Ackerman & Heggestad, 1997; DeYoung, Peterson, & Higgins, 2005; Judge et al., 1999; for relations between creativity and typical measures of intelligence, see DeYoung, Flanders, & Peterson, 2008). One potential reason for the inconsistent results is that relatively little research has examined the possibility that personality-cognition relations might vary as a function of age (but see Hultsch et al., 1999). This omission is unfortunate because in addition to determining whether the relations generalize to other segments of the population, examination of age relations could be informative about the nature of age differences in both personality and cognition. For example, an increase in the strength of the personality-cognition relation with increased age might suggest that the two aspects are becoming more closely integrated, or less differentiated, with increased age. Alternatively, a nearly constant relation between aspects of personality and aspects of cognition across the adult years would be consistent with the preservation of the distinction between the two dimensions of functioning across the adult years. There were two major goals of the current project. The first was to determine which dimensions of personality are related to which aspects of cognitive functioning. The second goal was to investigate whether the personality-cognition relations differed across adulthood. Among the desirable conditions for providing meaningful answers to these questions are a moderately large sample of participants across a wide age range, reliable assessment of major dimensions of personality, broad and sensitive coverage of cognition, and evidence that the relevant aspects of both personality and cognition are measured in a similar fashion at different ages. Personality-Cognition Relations 5 The current project attempted to incorporate these characteristics by examining data from a sample of 2,317 adults between 18 and 96 years of age who each completed the International Personality Item Pool personality questionnaire (IPIP; Goldberg, 1999) which assesses the “Big 5” personality traits, and also performed a broad variety of cognitive tests. The cognitive tests were selected to represent the four cognitive abilities indicated in Figure 1, and prior research (e.g., Salthouse, 2004; Salthouse & Ferrer-Caja, 2003; Salthouse, Pink & Tucker-Drob, 2008) has established that all of the variables have good reliability (i.e., coefficient alphas greater than .7) and validity (i.e., factor loadings greater than .7). There were four major phases to our analyses. Because we were interested in age relations, we first divided our sample into three age groups which approximately corresponded to the periods of young adulthood (18-39), middle adulthood (40-59), and older adulthood (60-96). Confirmatory factor analyses were then conducted to investigate the structure of the cognitive abilities and the personality traits and determine whether it is reasonable to assume that they were invariant across age groups. Next we converted the composite scores for the cognitive abilities and the scores for the personality traits into z-scores, and examined the age trends in the four cognitive ability variables and the five personality traits. Finally, we used the model in Figure 1 to investigate the relations between the personality traits and the cognitive abilities in each age group. It is important to emphasize that although Figure 1 portrays the personalitycognition relations as though personality was a cause of cognition, we are interested in the associations between the two domains, and we do not assume that either personality or cognition is necessarily more primitive or fundamental in the relationship between the Personality-Cognition Relations 6 two. The relations were examined in terms of regression coefficients rather than covariances because we were interested in identifying unique relations among the variables. However, it is worth noting that nearly identical patterns, with congruence coefficients greater than . 99, were found when the analyses were repeated with the personality-cognition relations represented by covariances instead of regressions. 1