There is nothing they enjoy more than sitting in front of the TV, watching celebrities at play and images of well-formed female bottoms. Human males, of course, are keen on it, too.

Scientists reported last week that male rhesus monkeys will 'pay' to check out pictures of female monkey bottoms or images of socially dominant members of their species.

The insight into monkey urges was arrived at by researchers at Duke University in North Carolina who gave male macaques the choice of looking at images on a computer screen of either a female's posterior or of a socially-dominant monkey. They found that the monkeys would take a cut in their fruit juice allowance for glimpses of either alluring vision. As they report in Current Biology magazine, the pleasures of pay-per-view television appear to be shared by more than one species. However, when the monkeys were offered visions of a social inferior monkey they refused to look unless they were paid extra rations.

'It is human nature to pay attention to powerful people,' said researcher Robert Deaner. 'Now it seems other primates share the tendency.' As for the bottoms, 'they reacted like men faced with a large billboard of a lingerie model,' said his colleague, Professor Michael Platt of the university's neurobiology department.

Platt and Deaner argue that these tendencies show how important it is for social animals like macaques and humans to be able to check out the status and reproductive prospects of fellow members of their species. 'This is not simply monkey pornography,' added Platt.

However, these tendencies are not necessarily those of female macaques. 'We have only done the experiment with males,' said Platt. 'Now we are preparing to do it with females. We may find they have similar attitudes but that is not really the perception we have of human females.'