Japanese Macaque monkeys groom each other sitting in a hot spring in the snow at Jigokudani Wild Monkey Park in Yamanouchi Nagano prefecture central Japan Monday Jan Male macaque monkeys pay for sex by grooming females according to a recent study that suggests the primates may treat sex as a commodity In primate societies grooming is the underlying fabric of it all Dr Michael Gumert a primatologist at the Nanyang Technological University in Singapore said in a telephone interview Saturday Jan Gumert found after a male grooms a female the likelihood that she will engage in sexual activity with the male was about three times more than if the grooming had not occurredbr