PARIS - Short people should pray for a return to the Seventies fashion of stack heels, for the power of jealousy depends on how tall you are, the British weekly New Scientist says.

Researchers at the University of Groningen in the Netherlands and University of Valencia in Spain asked 549 Dutch and Spanish men and women to rate how jealous they felt, and to list the qualities in a romantic competitor that were most likely to make them ill at ease.

Men generally felt most nervous about attractive, rich and strong rivals.

But these feelings were increasingly relaxed the taller they were themselves. The more vertically challenged the man, the greater his feelings of jealousy.

For women, what counted most in jealousy was the rival's looks and charm, but these feelings were less intense if the woman herself was of average height.

This makes sense in evolutionary terms, says New Scientist, in next Saturday's issue.

Taller men are most successful with women, and women of medium height enjoy the best health, fertility and popularity with men.

On the other hand, a woman of average height could in certain circumstances fall afoul of the green-eyed monster if their rival were taller.

"Taller women are more dominant and have greater fighting abilities than shorter women," says the study, which appears in the journal Evolution and Human Behavior.