Turning our noses up at sex pheromones
Cambridge & Great Eastern Regional Group: Human sex pheromones, fact or fiction?
Cambridge University, UK, 16 February 2006
The ability of sex pheromones to affect human behaviour was discussed by Barry Keverne, director of the sub-department of animal behaviour at the University of Cambridge at the meeting of SCI’s Cambridge & Great Eastern Regional Group on 16 February 2006.
The lecture opened with some audience participation. Paper strips with tiny quantities of putative human sex pheromone (androstenone) were very cautiously sniffed. The results were fascinating.
| About a third of the audience could not smell anything, and most of the others found the smells unpleasant or positively repellent |
About a third of the audience could not smell anything, and most of the others found the smells unpleasant or positively repellent (‘stale urine’ and ‘rank’ were some of the comments). Certainly, not very compelling evidence for their use as sexual attractants or aphrodisiacs. So beware! Products containing these materials are advertised, with appropriately lurid claims, and sold on the internet. Save your money!
After this revealing exercise, Keverne explained that the main problem with human sex pheromones is that all credible research indicates that, unlike many mammals (such as mice, rats and dogs), humans have virtually lost their ability to detect pheromones. In most mammals, the vomeronasal receptor is used for this purpose.
The key to human behaviour lies in the brain and the way that it has developed. Compared to other mammals, the human brain is disproportionately large,the proportion of the brain devoted to olfaction is much reduced and the proportion devoted to sight is massively increased. As a consequence, our ability to interpret and describe smells is very limited. For example, it is difficult to describe or imagine a smell. In short, our evolutionary history has made us primarily visual creatures. Our behaviour is also highly socially and culturally conditioned.
Apparently only two vomeronasal receptor genes are expressed in humans (compared to 300 in rodents). Could these be linked to sexual behaviour? There is limited evidence, but the most likely role for these receptors is thought to be mother–baby communication and bonding. There is evidence that babies are able to recognise the smell of their mothers. Perhaps this is the last stand of the human pheromones?
So the conclusion for sex pheromones? It is all in the mind! (Though we doubt that this news will affect the sales of Lynx aftershave and its wonderful marketing.)
John Wilkins
SCI Cambridge & Great Eastern Regional Group
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