Imagine a dating site where, in addition to a completed survey, you have to submit a genetic profile. This could be the future of matchmaking, especially now that some scientists think that our compatibility genes—the same genes that determine whether an organ transplant will take—play a role in sexual attraction.
Daniel Davis, an immunologist at the University of Manchester in England, tells the story of these distinct genes and their impact on our relationships in his new book, The Compatibility Gene: How Our Bodies Fight Disease, Attract Others, and Define Ourselves.
In a nutshell, can you explain the big idea—the thesis—of your new book, The Compatibility Gene?
The big idea is that a surprising amount of who and what we are comes from the way our species has evolved to survive disease. Put another way, this is about the idea that our immune system influences many aspects of human biology.
We each have a very similar set of genes—the 25,000 or so genes that make up the human genome—but there are variations that give us individual characteristics such as our hair or eye color. Crucially, the few human genes in this story—our compatibility genes—are those that vary the most from person to person. These genes are, in effect, a molecular mark that distinguishes each of us as individuals.
What role do compatibility genes play?
These genes are medically important because they influence the success of many types of medical transplants. These are the genes that doctors try to match in bone marrow transplantation, for example. And importantly, the versions of these genes that you have inherited influence which diseases you are susceptible or resistant to.
Other provocative research suggests that these very same genes also influence sexual attraction between two people, the wiring of our brains and the chance that a couple may have certain problems in pregnancy. We have no problem accepting that our physical characteristics—hair and eye color—are dictated by our genetic makeup. But can something that feels as intimate as choosing a partner be similarly influenced by our genetic inheritance? The subject is contentious, and there’s no simple answer. There is strong evidence that animals choose mates according to the versions of compatibility genes they have. There is evidence that something of this is true in humans, but the controversy is in establishing how big an effect this is—because human interactions are undoubtedly complex.
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