THE idea that we respond to pheromones secreted by other people has been
given a boost. Researchers have discovered that sweat contains odourless
substances that alert the brain to the presence of a potential mate.
Ivanka Savic and her team at the Karolinska Institute in Sweden wafted a
testosterone-like compound from men鈥檚 sweat and a female oestrogen-like
compound towards 12 men and 12 women.
PET scans of the subjects鈥� brains revealed that the hypothalamus, a region
known to be involved in pheromone detection in rats, responded differently in
men and women. In men the hypothalamus was activated by the oestrogen-like
compound, while women鈥檚 brains responded to the male chemical. The researchers
will report their findings in a future issue of Neuron.
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鈥淭his sexual dimorphism is a hallmark of the pheromonal response,鈥� says
pheromone expert Noam Sobel at the University of California, Berkeley. He says
Savic鈥檚 group is the first to show an effect in humans that is gender specific.
鈥淭hat鈥檚 what makes this finding special.鈥�
Researchers have previously found that female sweat may influence the
menstrual cycle of other women, while other studies suggest a role for
pheromones in sexual attractiveness. But the existence of human pheromones has
remained controversial, and Savic鈥檚 experiments are the first to show that our
brains respond to such substances.
But Savic is careful to point out that her study doesn鈥檛 prove the existence
of human pheromones. To do that, researchers will have to demonstrate that
behavioural or physiological changes occur alongside the brain responses. 鈥淲e
have to show the whole chain,鈥� she says.