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The Neurochemistry of Love

Love is a cocktail of brain chemicals.

 Loretta Breuning
Source: Loretta Breuning

Love stimulates all of your happy chemicals at once. That's why it feels so good.

But our brain evolved to motivate reproduction, not to make you feel good all the time. That's why the good feeling doesn't last.

When you understand your happy chemicals, you can build realistic expectations about love. That's the best way to make it last.

Each happy chemical rewards love in a different way. When you know how each one is linked to reproductive success, the frustrations of life make sense.


Dopamine is stimulated by the "chase" aspect of love. It’s also triggered when a baby hears his mother. Dopamine alerts us that our needs are about to be met.

Female chimpanzees are known to be partial to males who share their meat after a hunt. Female reproduction depends heavily on protein, which is scarce in the rainforest, so opportunities to meet this need trigger lots of dopamine. For humans, finding "the one" makes you high on dopamine.


Oxytocin is stimulated by touch, and by social trust. In animals, touch and trust go together. Apes only allow trusted companions to touch them because they know from experience that violence can erupt in an instant. In humans, oxytocin is stimulated by everything from holding hands to feeling supported to orgasm. Holding hands stimulates a small amount of oxytocin, but when repeated over time, it can build up a circuit that easily triggers social trust.

Sex triggers a lot of oxytocin at once, yielding lots of social trust for a very short time. Childbirth triggers a huge oxytocin spurt, both in mother and child. Nurturing other people’s children can stimulate it too, as can nurturing adults, depending on the circuits one has built. Friendship bonds stimulate oxytocin, and in the monkey and ape world, research shows that individuals with more social alliances have more reproductive success.


Serotonin is stimulated by the status aspect of love—the pride of associating with a person of a certain stature. You may not think of your own love in this way, but you can easily see it in others. Animals with higher status in their social groups have more reproductive success, and natural selection created a brain that seeks status by rewarding it with serotonin. This may be hard to believe, but research on a huge range of species shows tremendous energy invested in the pursuit of status. Social dominance leads to more mating opportunity and more surviving offspring—and it feels good.

When you receive the affection of a desirable individual, it triggers lots of serotonin, even if you hate to admit it. And when you are the desired individual, receiving admiration from others, that triggers serotonin too. It feels so good that people tend to seek it again and again.

Why did the brain evolve so many different ways to motivate reproductive behavior? Because keeping your DNA alive is harder than you’d think. Survival rates are low in the state of nature, and mating opportunities are harder to come by than you might expect. Your genes got wiped off the face of the earth unless you made a serious effort. Of course, animals don’t consciously intend to promote their genes. But every creature alive today has inherited the brain of ancestors who did what it took to reproduce.

Source: Loretta Breuning
Source: Loretta Breuning

There is no free love in nature

Every species has a preliminary qualifying event before mating behavior. Creatures work hard for any mating opportunity that comes their way. In the end, some DNA makes lots of copies of itself, while other DNA disappears without a trace. You may say you don’t care about your DNA, but you’ve inherited a limbic system that does.

Unhappy chemicals creep into your life as you seek love in all its forms. Animal brains release cortisol when their social overtures are disappointed. The bad feeling motivates the brain to "do something." It reminds you, in a way, that your genes will be annihilated if you don’t get busy. You don’t need to tell yourself that in words. Natural selection created neurochemicals that give you the message nonverbally.

Love often disappoints for a subtle reason that’s widely overlooked. A young child learns to expect others to meet their needs. Children cannot meet their own needs, so love equals survival to the young brain. Eventually you have to start meeting your own needs. When the expectation of being cared for is disappointed, it can feel like a survival threat. Childhood is a luxury evolved by mammals, but it comes with a painful transition from dependence to independence. Lots of cortisol is triggered as you learn that you cannot trust the world to meet your needs for you. This independence is natural, for a species can only survive if each generation learns to meet its needs without its parents. And if you had parents who were not trustworthy in the first place, you had more cortisol, sooner.

When disappointment in love gives you that bad cortisol feeling, your brain looks for ways to trigger good feelings. There are limitless ways to do that. Sometimes a person seeks a new mating partner, and sometimes a person focuses on nurturing children. Sometimes a person tries to contribute to society and sometimes a person uses violence to hold onto their "loved" ones. These behaviors seem very different, but they are all motivated by the expectation of happy chemicals. Expectations depend on the circuits each individual has built from life experience.

In modern times, many people expect romantic love to be part of their life all the time. Expectations were different in the past. Sex created children, and if you lived to middle age, you could expect to be surrounded by grandchildren. But people had the same basic neurochemistry. No matter how you learn to trigger happy chemicals, each burst lasts for a short time and you have to do more to get more.

Love triggers a cocktail of neurochemicals because it’s so highly relevant to survival. But it cannot guarantee non-stop happiness. It feels like it can while you’re enjoying the cocktail, however, so your brain may learn to expect that.

This is an excerpt from my book Habits of a Happy Brain: Retrain your brain to boost your serotonin, dopamine, oxytocin and endorphin levels.

More from Loretta G. Breuning Ph.D.
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