Sweat linked to men's willingness to work with one another - Study

A pheromone contained in male sweat has been shown in tests to increase men's willingness to work with one another.

The chemical, androstadienone, has previously been linked to how attractive women find men but the new research suggests it also has an effect on other men.

ts apparent role in encouraging men to cooperate with one another could be a factor in explaining how men bond in team games, in fighting wars and even in building civilised societies.

Leaders, it found, were likely to co-operate with high and low status males because it is in their interests to maintain the structure of their society.

However, those of low status, are more likely to try to find ways to win themselves a big advantage at the expense of someone else, perhaps in an attempt to become upwardly mobile, the study suggests.

Researchers from the University of Turku, in Finland, found the effect androstadienone has on men when they carried out tests among computer game players.

They discovered that if men breathed in the pheromone they were much more likely to cooperate with players to do better at the game.

During the study 40 male volunteers, with an average age of 26, were asked to play the Ultimatum Game or the Dictator Game.

Half of them were asked during the tests to stiff deeply from a jar containing androstadienone mixed with dry yeast.

In both games players bargain over the share-out of €20, making and receiving offers to decide which of them should receive the most.

Previous research has shown that those making offers, the proposers, co-operate better when the other person, the responder, is attractive.

But the Finnish study is the first that has indicated that pheromones can influence how two men will respond to each other.

To our knowledge, this is the first study to show that androstadienone directly affects behaviour in human males, said Dr Paavo Huoviala and Dr Markus Rantala.

The pheromone is linked to the production of testosterone and as such indicates how dominant a male is likely to be in his social group.

In their report on the tests, published online by PLoS ONE, the researchers said pheromone was acting as 'a chemical equivalent of the peacock's tail' by intimating the dominance and fitness of a male.

Such information is believed to help women select a mate but is also important information for men because it can help prevent conflict and, the study suggests, improve cooperation.

The researchers were particularly interested to note that the cooperation was strongest among the high testerone, high dominant males.

This, the research suggests, might be because it is in their interests to maintain the social order: 'High status males also seem to favour cooperation more strongly.

'This would provide especially strong incentives for others to cooperate with high status individuals, as cooperation brings both immediate and delayed benefits, while costs of a possible conflict are likely to increase with the status of the opponent.'

Those men with lower testosterone levels, and thus likely to be less dominant, were found to be more likely to work purely for their own rather than the group's self-interest.

While they were likely to co-operate with the high status males, they were happy to try to score an unfair advantage over someone of similar of rank.

'Low status individuals do not treat each other fairly, while high status individuals are fair to both low and high status individuals,' the researchers said.