“Love is in the air” – a well-known phrase, seemingly metaphorical. However, the discovery of human pheromones brings into question if we can really smell love. How do pheromones shape the choice of a potential partner?
What are pheromones?
Pheromones are signalling molecules used within the same species. Using pheromones from bodily fluids, animals can share information with other related animals. The most well-researched pheromones are those signalling reproductive maturity, which are released in conditions optimal for reproduction. Females are considered to be able to discern between males based on the amount of pheromones released, thus exercising selectivity which ensures survival of the species.
However, further research into pheromones has shown that they play a role in all aspects of animal behaviour. In colony-forming insects, pheromones are key in the forming and maintain a community. Some species can produce pheromones when endangered and thus warn other individuals, with such molecules being looked into as a potential eco-friendly pesticide.
Human pheromones?
The discovery of pheromones in a large number of animal species has prompted a search for human pheromones. Articles across the internet mention several molecules, steroid hormones androstadienone, estratetraenol, androstenone and androstenol. Androstenone and androstenol, molecules with a pheromonal effect in pigs, have been found in human armpits.
Even so, further research on the effect of these molecules on human behaviour hasn’t definitively demonstrated a change or lack of change in behaviour caused by pheromones. While some studies have shown that men behave differently in social situations after being exposed to estratetraenol, other studies have shown that androstadienone and estratetraenol do not affect attraction. Although a consensus on this topic has not yet been reached, the current position is that these molecules are not human pheromones.
The only molecule that still seems promising in the search for the first human pheromone is secreted from Montgomery glands. These glands surround the nipple and their excretions encourage suckling in newborns. This behaviour can be noted in all babies, regardless of whether the pheromones come from their own mothers or not.
Can we scent love?
Despite shaky scientific foundations, the idea of human pheromones is fascinating to both the scientific community and the larger public. Many are even selling some of the researched molecules in the form of a perfume, claiming to increase attraction. Nevertheless, current findings indicate that we haven’t yet found the first human pheromone – all that remains is to await further research.
Literature
2. Wyatt TD. The search for human pheromones: the lost decades and the necessity of returning to first principles. Proc Biol Sci. 2015, 282(1804).
3. Hare RM, Schlatter S, Rhodes G, Simmons LW. Putative sex-specific human pheromones do not affect gender perception, attractiveness ratings or unfaithfulness judgements of opposite sex faces. R Soc Open Sci. 2017, 4(3).
4. Oren C, Peled-Avron L, Shamay-Tsoory SG. A scent of romance: human putative pheromone affects men’s sexual cognition. Soc Cogn Affect Neurosci. 2019, 14(7), 719-726.