Aug. 10, 2006 -- Grumpy and brainy may go together in older folks; but young people tend to be more open and friendly if they're bright, researchers report.

The study looking at the connection between personality and intelligence was presented today at the American Psychological Association's 2006 convention in New Orleans.

The researchers -- York University's Thomas Baker, MA, and Pennsylvania State University's Jacqueline Bichsel, PhD -- wanted to see if higher intelligence test scores matched up with any of five personality traits: openness, extroversion, agreeableness, conscientiousness, and neuroticism.

Neuroticism didn't appear linked to intelligence test scores at any age.

But, among younger subjects (19-60), openness and extroversion, or friendliness, were tied to higher intelligence scores.

This was not so for the older group (61-89). Instead, a lack of agreeableness was a predictor for the highest test scores in those over 60.

That is, high scorers tended to be grumpier in the over-60 group.

The results suggest "that a disagreeable nature goes hand in hand with advanced vocabulary and general knowledge in old age," the researchers write.