London, Nov 6 (IANS): People look for candidates with a healthy complexion when choosing leaders, says a study, adding that they do not favour intelligent-looking candidates except for positions which require negotiation between groups or exploration of new markets.

"It always pays for aspiring leaders to look healthy which explains why politicians and executives often put great effort, time and money in their appearance," said assistant professor Brian Spisak from the VU University, Amsterdam.

Looking intelligent is an optional extra under context-specific situations whereas the appearance of health appears to be important in a more context-general way across a variety of situations, Spisak added.

For the study, the team asked 148 women and men to imagine that they were selecting a new CEO for a company and to repeatedly pick between two photos of male faces.

For each choice, the participants were given a job description that specified the CEO's main challenge.

This was either to drive aggressive competition, renegotiate a key partnership with another company or lead the company's shift into a new market.

In each choice, both photos were of the same man but it had been digitally transformed. His face had been made to look more or less intelligent while his complexion was changed to look more or less healthy.

Researchers found a stronger general preference for health than intelligence.

The participants chose more healthy-looking faces over less healthy-looking faces in 69 percent of the trials.

"More intelligent-looking faces were only preferred over less intelligent-looking faces for the two challenges that would require diplomacy and inventiveness: re-negotiating the partnership and exploring the new market," Spisak concluded.

The results were published in the journal Frontiers in Human Neuroscience.