At one level, this is a story about six decades of research—and not a single recent breakthrough experiment. But through putting it all together, a new and fascinating theme emerges; that there are far-reaching consequences from the way our body fights disease. Not least is that this knowledge gives a new view of why our own uniqueness is fundamentally crucial.
For the way our body fights disease, it is beneficial to keep these genes exceptionally diverse. It would be no good if one sweeping infectious disease that killed people with certain versions of these genes would simply narrow the variation in these genes that got passed on to the next generation and lower our chances against other diseases in the future. This science has a powerful message for society: Nobody has a perfect set of compatibility genes. It’s our great genetic diversity that’s essential.
What two or three people are most likely to try to refute your argument? Why?
As I said, controversial experiments indicate that these immune system genes can also play a role influencing sexual attraction between people and the likelihood of couples having particular problems in pregnancy. One experiment in this line of thinking used a very unusual protocol for scientific work. Women were to refrain from sex for two days, use a nasal spray to keep their nostrils clear, read Patrick Süskind’s novel Perfume—about a man with olfactory hypersensitivity who is obsessed with people’s smells—and then come into the lab to smell a collection of T-shirts worn by men who hadn’t showered for two days. The experiment yielded the astonishing result that T-shirts worn by people with different compatibility genes smelt the sexiest. This seems to indicate that we subconsciously prefer sexual partners who have different compatibility genes from ourselves.
One problem is that it’s hard to know if any difference in smell detected here would actually influence a person’s behavior. There is strong evidence of this in animals, but for humans, relationships are more complex. Scientists differ in their views on this.
Who will be most affected by this idea?
This book gives new insight into how the human body works, and makes the link between immunity and attraction. So, just like learning about the idea of evolution itself, my hope is that one's life is simply enriched by these basic insights into human behavior: “Wow, so this is how it works.” I hope to get across a new view as to why we are each special on a molecular level and that there is a fundamental importance to our uniqueness.
How might it change life, as we know it?