Love at first smell

It's been a while since I last wrote anything scientific here, but then I was engaged in conversation with someone on noise.cash, and they didn't know about this attraction model so I thought of writing it down just for a change.

I’ve always been curious about what determines attraction between people. They say it’s all about that animal instinct… but they’re not entirely wrong, actually. Yes, men will find attraction in a girl with wide hips or in large chests because nature will dictate that those kinds of women would provide healthy children. While most women, on the other hand, tend to lean towards those bad boy kinds, those that look strong. But in the end, it all boils down to how they’ll help each other survive.

You may have heard of the pheromone thing mentioned a lot in sci-fi movies or in fiction books that boost sex appeal? That thing isn’t real. Well, not for humans at least, but it is a thing for animals and it’s the major driving force for them finding mates (Don’t ever trust products that advertise pheromones in their items because those often contain pig pheromones; which is the closest you can get to human pheromones). Scientists still can’t even figure out what makes up the human pheromone is yet, or if they do have an idea of it, it’s just non-conclusive. But what is a good basis of love is the major histocompatibility complex (MHC)

What is MHC?

The MHC codes your proteins on the surface cells. This complex helps your body recognize immune system invaders. It also regulates immune functions. But more than that, it actually is the key to helping you find the perfect partner. It’s probably the closest thing we humans have that can be called pheromones.

How to detect that MHC? Same as animals do, we detect it by scent. Sounds weird to go about sniffing people just to find a partner, right? But scent really has a lot to do with attraction. The more diverse the MHC of a person, the more attracted you get to them because their scent becomes more appealing to you. I found a study that the more diverse the smell is, the more attractive a person becomes. It’s designed this way so that you stay away from people that smell like you. I also believe that it’s like that so that inbreeding doesn’t happen and so that you don’t accidentally end up dating a close relative.

But what about love at first sight?

I'm still not sure about that, but I have seen some papers say that it's still based on the impression your scent gives off, even if it's from a distance, your innate scent will still reach some people.

I just find it fascinating because unconsciously, our bodies are still looking for a way to get stronger. You see, the more different a person’s MHC is, the stronger their immune system is, and usually, they have the opposite immune system from yours. Our bodies just want to get a better immune system that they want to pass down to future generations. And one thing I like about this specific topic is that it doesn’t just apply to heterosexual couples but also homosexual couples. It’s one of the most ideal models of attraction that I believe in because when cohabitation happens, both partners try to adapt that difference in their immune systems, and sometimes, it's a reason why people say couples often look similar. It's a minor consequence of trying to adapt a better immune system.

So I guess the saying “Opposites attract” holds true? Only in this case. Well, just with the immune system part, your body will still aim to find a partner that has a very similar biological make-up to yours. I mean, almost all of us have a 99.9% similarity with genetic make-up, the MHC is the 0.1% difference that we have. There’s also this study about assortative mating, where “like attracts likes” make better sense. But this model of attraction is mostly aimed to preserve a specific quality. It’s not close to inbreeding, but it’s just a way to pass on a trait to future generations like height, eye colors, hair colors, etc.

What about if I use perfume? Won’t that make it hard for people to catch my scent?

Not really, you see, the kinds of perfume choices you have are actually matched to how you perceive your own scent. So perfumes and colognes won’t ever mask your natural scent, if anything, it enhances it. This is actually where the saying that “A good smelling person will always be attractive” because their MHC is boosted. Perfumes and colognes actually provide a way to alert potential mates about your presence, it also gives them a general impression of your health.

Primary source:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6333523/pdf/nihms-1509206.pdf