Monogamy is cute, but what does your Brain have to say about it?

Dearly Beloved,

Let’s begin with a scandalous confession…I’m not here to ruin your candlelit dinners, nor do I want to steal your wedding Pinterest board dreams. But I am here to gently dismantle the idea that humans are supposed to be monogamous. I mean, it is an adorable idea. But like low-rise jeans and veganism, it doesn’t fit everyone.

And your brain? Oh, she agrees.

The myth of true love aligns itself perfectly with the emergence of agriculture, politics of ownership and the drawing of the state-lines. Society likes a simple narrative: You meet The One, form a lifelong bond, and somehow never fantasize about your barista again. This belief, called amatonormativity, assumes that everyone thrives in a romantic, exclusive, long-term relationship. Bonus points if you share a mortgage and a Netflix password!

But let’s get something straight: Nature didn’t build us to only monogamy. It built us to attach, detach, reattach, explore, bond again, or just vibe. And your brain? She’s doing her own thing behind the scenes, often without consulting your relationship goals.

So let’s meet the chemicals running our romantic life. Behind every “Good morning, babe” and “We need to talk” are dopamine neurons and vasopressin receptors (don’t worry, they don’t bite). Here’s the quick and dirty version: Dopamine neurons come in 2 varieties (D1 & D2).

D2 neurons = forming new bonds (aka the honeymoon phase)
D1 neurons = maintaining long-term bonds (aka when your partner snores at night and you still stay in the relationship)

Both have little doorbells of Vasopressin receptors (called AVPR1a receptors). When they vasopressin binds to these receptors, the doorbell rings. These little doorbells are found on each of the Dopamine neurons.

If the doorbell rings on the D2 neuron, your body exclaims: “Let us spend the whole weekend under the sheets, getting to know each other and drink mimosas till we collapse!”

While if you ring the doorbells on D1 neurons, your mind wishes to “move in, tie the knot, co-parent a dog or a cat, or even get a couple/throuple’s gym membership!”

Depending on which neuron’s doorbell is active, your body decides to either “Let’s merge calendars” or “Thank you, next please.”

If your D2 neurons never make the handoff to D1, you might: Lose interest fast — Become a serial monogamist or just prefer casual/multiple partners without the need for a partnership. Sound familiar? That’s not you being “non-committal.” That’s literally neurochemical programming. It is how you are wired.

But what about these evolutionary arguments we see— apparently according to these we were wired to be monogamous. Oh, we’re going there!

If humans were meant to be monogamous, we’d probably have smaller testicles. Stay with me. In primates, the more promiscuous the species, the larger the testicles (to compete in what scientists adorably call “sperm wars”).
Gorillas? Very monogamous. Tiny balls.
Chimps? Wildly promiscuous. Testicular giants.
Humans? Right in the middle.
Translation: Nature left the door open for us to have options.

Here are some more Wild Facts your Bio Teacher forgot to mention

Moaning during sex in female mammals is most common in species where females have multiple partners. It’s an evolutionary “come and get it” shout-out.

The human penis shape? Possibly evolved to scoop out any previous sperm left behind by the previous partner (romantic, right?). Evolution doesn’t do subtle. Technically, the “first one to finish” doesn’t really win the race. Once the sperm gets scooped out, it can be replaced by the new squirt.

“Kamikaze sperm”—yes, real term—exist to block other sperm from reaching the egg. They’re the bouncers of the reproductive world.
TL;DR: Your body is not monogamous by design. It’s flexible by evolution.

“Okay, But I Like Monogamy.” Fabulous! Monogamy is a valid and beautiful relationship structure. But it’s not the only natural one. Some people feel safest with one partner, one toothbrush cup, one shared Amazon Prime account. Others thrive in relationships where intimacy is abundant but not exclusive.

Some people try monogamy, realize they were more into the wedding playlist than the concept of forever, and move on.

All of this is normal.

Final Thought: It’s Not You, It’s Neurochemistry

Before you write that guilt-text to your therapist about “catching feelings for someone else,” take a breath. Your brain isn’t betraying you. It’s just doing what it evolved to do: seek connection, novelty, safety, and pleasure. Sometimes all at once. So whether you’re monogamous, polyamorous, relationship-anarchist, or just flirting with the concept of commitment, know this: You are valid. Your wiring is valid. And your love style deserves respect—whether it fits the fairy tale or not.

Homework (the fun kind)

Here’s a journal prompt for you…“If no one judged me, what kind of relationship would I naturally choose?”
Because maybe the healthiest relationship of all is the one where your brain and your heart get to be on the same team and they are not forced to adapt in order to exist the way they show up.

Yours in scandal, science, and serotonin,
Nixi
(Your Friendly Neighborhood Neuroscience and Sex Researcher)