London, July 14 (Reuters): Being intelligent is no guarantee of a happy old age, researchers said today.

They studied 550 people born in Scotland in 1921 whose mental ability had been tested at age 11 and again at 80 to determine if intelligence over a lifetime was linked to happiness.

“In older people there seems to be no relationship between how well they do on tests of their mental ability and thinking memory skills and how satisfied they are with their life,” said Alan Gow, of the University of Edinburgh in Scotland.

The study, which is published in the British Medical Journal, looked at how people maintain their mental ability as they age and the impact it has on their lives in an effort to discover the secret of successful ageing.

In addition to the intelligence tests, the elderly people completed a satisfaction with life survey in which they rated how content they were. The researchers found no relationship between satisfaction scores and cognitive ability.