Our genetics strongly influence attraction. The specific genes that are most important for attraction are called our human leukocyte antigen (HLA) genes, which are essential for our immune system. But why would the immune system—the system that protects us from getting sick—be involved in the attraction response? Why should the thing that determines whether I catch a cold also decide whether I catch feelings?
Back when humans were first evolving, before we had grocery stores and streaming services and hospitals, we were just as susceptible to environmental pressures as any other wild animal. Famine, predators, and, very importantly, diseases took out many humans who were ill-equipped, unfit, or just plain unlucky. If people were investing their time and resources into offspring, then they had to make sure that those offspring would be healthy enough to live through these pressures.
“If people were investing their time and resources into offspring, then they had to make sure that those offspring would be healthy enough to live through [environmental] pressures.”
But how did humans make sure that they were making the healthiest children possible? The answer lies in genetics. Your HLA genes play a huge role in whether you’re likely to catch certain things. Wouldn’t it be better to be immune to everything? Unfortunately, we don’t have enough space for that. Each person only has a certain amount of “spaces” in their HLA gene set that can be filled with immunity to certain diseases.
Let’s look at it this way: say that your HLA gene set is like your smartphone. You can only fit so many apps on it before it’s full, and you don’t get to choose a smartphone’s default apps. The same is true of everyone else, too. If you and a partner with a different phone and a different set of apps have a baby, then that baby will get a randomly assigned set of apps from your and your partner’s phones. If you and your partner have a lot of similar apps, then your baby might end up with three ride-share apps, two calendars, and four meditation apps, but with no streaming services or clocks! Wouldn’t it be better to set your baby up with less redundancy and, instead, give them a full set of useful tools?
Immune genes operate in the same way, except that the consequences of redundancy are much higher than just getting two Uber apps and a Lyft app. If your child has too much immunological redundancy—say, if they have five markers protecting them from the bubonic plague but nothing to protect them from the bird flu—then they will be more susceptible to disease and death. Partners with a very different set of immunological markers would give you a better chance of having children with immunity to a higher number of various diseases, thereby giving it a better shot at a healthy life. Biology has, thus, found a way to make those people more attractive to us as potential partners.
“If your child has too much immunological redundancy—say, if they have five markers protecting them from the bubonic plague but nothing to protect them from the bird flu—then they will be more susceptible to disease and death.”
We all release different smells that tell other people what our disease immunities are, and when we happen upon someone with a totally different set, we smell that and find them to be attractive. This is what we talk about when we say that there was “chemistry” or a “spark” when we meet someone who we like. Different gene sets can make others irresistible while similar sets make them fall flat, and it cannot be changed or forced, no matter how much you want to like a person. We are who we are, genetically. Lucky for us, we now live in a time where we can use an app that, for the first time, accepts and works with that and with who we fundamentally are.
It’s a wonderful time to search for love now that we have an actual online dating platform that uses science. To learn more, visit pheramor.com, and catch our Pheramor Phriday show every Friday at 3 pm CST on Facebook Live, hosted by our lead geneticist, Dr. Brittany Barreto.