Fragrance companies have invested hundreds of millions of dollars on the assumption that scent is a major factor in attraction. But perfumes mask one's natural odor, and that could be a bad thing when it comes to choosing good genes. Time and again, so-called t-shirt experiments have shown a link between body odor and differences between the major histocompatibility complexes (MHCs) of the sniffer and the sniffed.
In a typical test, a subject will rank the pleasantness (or otherwise) of t-shirts worn overnight by members of the opposite sex. The t-shirt picks up the scent of its wearer, the result of a complex, poorly understood interaction between the MHC-mediated skin compounds and the microbial fauna that feed upon them.
Despite strong and surprising evidence that the differences people perceive have a genetic basis, it's unclear what they actually do with that information. The MHC is the most variable region of ...
