Be Quick, Live Longer?

The new research was detailed in the January issue of Psychological Science, a journal of the American Psychological Society. It involved 898 people aged 54-58 in Scotland who took part in a 1988 study that measured their IQ and reaction time -- how long it took to press a button once prompted -- plus various health factors.

Over the next 14 years, 185 of them died. The new study simply compared the living to the dead based on intelligence and quickness.

Higher IQs were linked to living longer, but reaction time was a stronger predictor, the review found.

"The cause of the relationship is unknown," Ian Deary of the University of Edinburgh and colleague Geoff Der write in the journal.

While reaction time is thought to be somewhat related to IQ, it is seen as a simpler assessment of the brain's ability to process information, because reaction time is not likely to be very related to knowledge, education, or background, researchers say.

An obvious question comes to mind: Might training to improve your smarts or reaction time help you live longer? Nobody knows.

Deary and Der caution that slow reaction times might reflect a degeneration of the brain, which in turn could reflect degenerating physical health.

A separate study released in 2003 found a curiously mixed result. With 70 years of data to on nearly 1,000 people, also in Scotland, researchers found people in poor neighborhoods lived longer if they had high IQs. But IQ didn't predict longevity for people in wealthy neighborhoods. Maybe the smarter people learned better health behaviors early in life, the researchers speculated. Or perhaps superior mental skills simply help a person cope with problems better.

More study is needed to figure all this out.

"It is only in the last few years that we have come to realize that IQ-type scores are related to mortality, even when the mental tests were taken decades before death," Deary said. "Now, several research teams have replicated this finding. What we need to do now is understand it. We and others are following up several possible explanations for this intriguing new association between intelligence and survival."