New York, May 8 (IANS): Male voices are not deeply pitched in order to attract female mates but to dominate the competition with other males, finds a new study that analysed a wide variety of primates including humans.

"We wanted to determine if sexual selection had produced sex differences in humans and closely related species," said David A. Puts, associate professor of anthropology, Pennsylvania State University.

The findings showed that a deep-pitched male voice was seen as dominant by other males but had a smaller impact on attracting females.

Human male traits imply physical aggression and formidability and seem to provide competitive advantages in fighting or threatening other men more than they help attract women.

"We find that masculine traits in humans are not the same as, say, in peacocks where the beautiful tail attracts a mate," said Puts in the paper published in the journal Proceedings of the Royal Society B.

Also, the researchers found that the depth in the female voices did not affect how attractive they were deemed by male listeners.

However, deeper male voices were rated as more dominant by men and more attractive by women.

In addition, in men with low levels of the cortisol -- stress hormone -- a higher level of testosterone was linked to a deeper voice.

"Men who have higher testosterone and lower cortisol have a stronger immune response," Puts said.

In a the three-part study, the team of researchers explored the links between voice pitch and mating systems, attractiveness and for males only, perceived dominance.

They looked across the anthropoid primates -- those most closely related to humans, including gorillas, chimpanzees and orangutans.