A new psychological study reported by researchers Thomas Baker of York University and Jacqueline Bichsel of Pennsylvania State University compared the cognitive capacities of older and younger adults. Diagreeableness and intelligence are positively correlated in older adults according to the press release describing the findings:
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.
ScienceDaily publishes the complete press release of the study here.