Personality Predictors of Intelligence Change From Younger To Older Adulthood

An ability to be open to new situations may predict intelligence earlier in life, says a new study, but disagreeableness may predict intelligence later in life. According to the findings, differences in personality predictors of intelligence were found between young adults, and those who retain a normal level of overall cognitive ability in old age and those older adults who are cognitively superior. This study's results will be presented at the 114th annual convention of the American Psychological Association (APA).

Previous investigations of personality-intelligence relationships sampled mainly young adults. This study, conducted by Thomas Baker MA, of York University and Jacqueline Bichsel PhD, of Pennsylvania State University, is the first time both young and older adults are compared on what personality traits predict intelligence in a sample of 381 adults aged 19 to 89 years old. The participant's education level ranged from some high school to graduate degree completion. The sample group was separated into three groups a) young adults (18-60), b) older adults who were cognitively comparable to the younger adults (18-60), and c) older adults who were cognitively superior to both the first and second group (over 60). The older group was separated according to the scores received on a battery of standardized intelligence and personality tests.

Personality predictors of cognitive abilities differed among the three groups studied. Openness and extraversion were important predictors of general knowledge in young adults, presumably the time of life when general knowledge increases fastest, with those higher in openness and lower in extraversion scoring higher on general knowledge. Openness was found to be a strong predictor of young adults' ability to retain general knowledge and store short-term information.

But, in the case of older cognitively comparable adults, personality traits of openness and extraversion had little or no impact on their ability to retain general knowledge. Overall within this group, personality appeared less important in explaining overall differences in cognitive abilities compared to the younger group.

In the cognitively superior older group, who outperformed both the cognitively comparable older adults and the younger adults on every ability tested, "agreeableness was found to have a contrary relationship with general knowledge suggesting that a disagreeable nature may go hand in hand with better vocabulary and knowledge retention in older age," said Baker. This result supports previous research that suggests that those who are highly intelligent may be more aloof and independent.

Interestingly, conscientiousness and openness were predictors of strong short-term memory and visual and auditory processing in older adults, suggesting that "conscientiousness does not necessarily make one "smarter" but could enable older individuals to perform better on tests," said Baker.