The Guardian on whether humans have the ability to smell out suitable partners/mates, based on an upcoming book by Daniel M. Davis, The Compatibility Gene: How Our Bodies Fight Disease, Attract Others, and Define Our Selves:
The basis for this notion is the so-called smelly T-shirt experiment, first performed by a Swiss zoologist called Claus Wedekind in 1994. He analysed a particular bit of the DNA of a group of students, looking specifically at the major histocompatibility genes (MHC). The students were then split into 49 females and 44 males. The men were asked to wear plain cotton T-shirts for two nights while avoiding anything – alcohol, cologne etc – that might alter their natural odour. After two days the shirts were placed in cardboard boxes with holes in them, and the women were asked to rank the boxes by smell using three criteria: intensity, pleasantness and sexiness.
Wedekind’s results appeared to show that the women preferred the T-shirts worn by men with different compatibility genes from themselves, raising the possibility that we unconsciously select mates who would put our offspring at some genetic advantage. The experiment was controversial, but it did alter scientific thinking about compatibility genes. And while the mechanism behind this phenomenon is poorly understood, that hasn’t stopped dating agencies from employing MHC typing as a matchmaking tool.
Of course, there are labs out there taking advantage of this science:
One lab offering such testing to online agencies (you can’t smell potential partners over the internet; not yet), a Swiss company called GenePartner, claims: “With genetically compatible people we feel that rare sensation of perfect chemistry.”
But take all this with a big grain of salt, as the research is still preliminary and no one really understands how all this works:
It is not completely understood how all this works at the molecular level, but it is at this forefront that Davis toils. “My research is in developing microscopes that look with better resolution at immune cells and how they interact with other cells,” he says. This interaction is “reminiscent of the way neurons communicate” in the brain, raising the possibility that your compatibility genes are responsible for more than just fighting infection, and could even influence how your brain functions. I confess to Davis that I don’t really understand this part. “None of us do,” he says. “I just happened to write a book about it.”
But how does the smelling thing work – if it works? It has been shown that mice can, and do, detect compatibility genes by smell, and that stickleback fish also choose mates by their odour, but in humans, Davis admits, the jury is out. “How it works on the olfactory level is basically not understood at all,” he says.
I think the more interesting point from Davis’s research is this: since each human responds slightly differently to any particular disease, in the not-too-distant future vaccines and other medications may be tailored to match our compatibility genes.