Major Histocompatibility Complex
• Amorous Research
A scientist on the biochemistry of sexual attraction:
... Fascinating work on genetics and mate preferences has shown that each of us will be attracted to people who possess a particular set of genes, known as the major histocompatibility complex (MHC), which plays a critical role in the ability to fight pathogens. Mates with dissimilar MHC genes produce healthier offspring with broad immune systems. And the evidence shows that we are inclined to choose people who suit us in this way: couples tend to be less similar in their MHC than if they had been paired randomly.
How do people who differ in their MHC find each other? This isn’t fully understood, but we know that smell is an important cue. People appear to literally sniff out their mates. In studies, people tend to rate the scent of T-shirts worn by others with dissimilar MHC as most attractive. This is what sexual “chemistry” is all about.