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.
Searching for a Connection
The study included 381 healthy adults, age 19-89, who took personality and intelligence tests.
Researchers split participants into two age groups, with age 60 as the dividing mark.
The younger group (aged 19-60) didn't outscore their elders on any of the intelligence tests.
The researchers add that other studies, unlike theirs, have linked grumpiness to intelligence in "highly intelligent young adults (ages 17-39)."
If that's true, it suggests "that a disagreeable nature may foster intellectual achievement that in turn leads to cognitive vitality in old age," write Baker and Bichsel.
However, the study doesn't pinpoint which came first: personality or intelligence. Participants weren't studied as they aged to see if their personality or intelligence changed.
License to Be Grumpy?
Don't try to flip the findings around or jump to conclusions about the IQs of people you know.
The study doesn't mean grumpiness makes people smart as they age, or that all open-minded young extroverts are brilliant. Or that friendly, upbeat elders and disagreeable youths are dumb.
Also, remember all the older participants had clear minds. Dementia isn't a normal part of aging, but it's more common later in life. So this study doesn't represent a cross section of older adults.
Speaking of memory, the researchers also noticed that short-term memory test scores were better for the over-60s who scored high on conscientiousness and openness.
"Conscientiousness does not necessarily make one 'smarter' but could enable older individuals to perform better on tests," Baker says in an American Psychological Association news release.