Eau De Genes

Natural History, June, 2001 by Kirsten L. Weir

EAU DE GENES Scientists and Lovers alike have long known that fragrance plays a role in sexual communication. Now, research done by Manfred Milinski and Claus Wedekind while they were at the Universitat Bern in Switzerland suggests some evolutionary explanations for odor preferences.

A set of genes involved in both scent recognition and conferring immunity to infection--known as the major histocompatibiLity complex (MHC)--is widespread in vertebrates. Both mice and humans, for example, have been shown to prefer the body odor of partners that possess MHC genotypes different from their own.

Milinski and Wedekind asked both women and men to assess various scents, indicating whether they would "like to smell like that" themselves or whether they would like to smell them on a partner. There was a positive correlation between the subjects' own MHC genes and the scents they chose for themselves--but a negative correlation for fragrances they selected for potential partners.

The researchers believe that people prefer fragrances that amplify--rather than mask--their natural body odor. By using perfumes that broadcast their genetic makeup to potential mates, and by selecting partners whose MHC genes are dissimilar to their own, individuals may reduce inbreeding as well as susceptibility to certain diseases. ("Evidence for MHC-Correlated Perfume Preferences in Humans," Behavioral Ecology 12, 2001)