New York, Sep 24 (IANS): Women living where rates of infectious diseases are high, according to a theory, prefer men with faces that shout testosterone when choosing a mate. But a study suggests otherwise.

"It is not the case that women have a universal preference for high testosterone faces and it is also not the case that such a preference is greater in a high-pathogen environment," said anthropologist Lawrence S. Sugiyama from the University of Oregon.

And the opposite is also the case.

"Men do not uniformly appear to have a preference for more feminine faces, at least within the ranges of cultures shown in this study," Sugiyama added.

The new study tested 962 adults drawn from 12 populations living in various economic systems in 10 nations.

The closest the study came to confirmation was in market economies in the study populations in Britain, Canada and China, perhaps because preferences shift in response to the local range of variation in traits, and men in market economies have higher testosterone.

"In large-scale societies, we encounter many unfamiliar people so using appearance to infer personality traits can help cope with the overwhelming amount of social information," Sugiyama said.

For instance, in all cultures tested, high testosterone faces were judged to be more aggressive, and this is useful information when encountering strangers.

Sugiyama and co-authors contributed to the study based on their work with the Shuar - a rural population with a long history of warfare in Ecuador and whose mixed economy today is based on horticulture, hunting, foraging and small-scale agro-pastoralism.

The study appeared online in the journal Proceedings of the National Academy of Sciences.