Here’s a little more info on the sweat/MHC study we talked about yesterday. It seems that women prefer mates with MHCs very different from their own. That seems like a good idea – it helps provide diversity within the genome. It would be hard to get a sample from every guy and bring it to the HLA-typing lab, but no need: the brain can detect MHC differences by smell (they’re associated with pheromones)! Weird. And cool.