Love is in the airI love you. Because you smell different than I do. Not quite Titanic or Casablanca or even Olivia Newton-John in Grease. But smells may be part of the reason why we fall in love with a certain person. At least that is what a new study argues.
We've known for awhile that animals find their "true love" partly through smells. One of the things they are sensing is whether the potential mate has a different set of MHC genes.
MHC genes are a big part of our immune system. These genes are used to create the huge number of antibodies that we each make to battle bacteria, viruses, etc. Everyone has a different set of these antibodies.
The more varied your MHC genes are, the more invaders your immune system can recognize and defeat. So two parents with very different MHC genes will have kids with immune systems that can recognize (and so defeat) lots of different kinds of bacteria and viruses. Parents with similar MHC genes will have kids with less varied immune systems. (This is a big reason why inbred animals are so sickly.)
Animals can tell about a potential mate's MHC genes through smell. And people might be able to do this as well.