This is your brain on flirting

There are roughly 124 million single adults in this country, which means more than half of the adult population is unattached. Yet for people looking for love, the dating landscape can feel less like an ocean and more like a desert. Why? Because the challenge lies in meeting people. Meeting them, liking them, and getting them to like you back.

This is where flirting comes in.

Like most animals, humans have mating rituals. The male bowerbird builds a neat little nest, complete with shiny shells and buttons, to attract females, while the male human wears a snappy suit. The female chimp shows off her swollen buttocks, while the female human shows off her hip-to-waist ratio in a mini-dress. And both male and female humans engage in a complex ritual called flirting.

Watch Fusion’s special “The Search for Sexy” for more on the science of how we date and mate today.

Yes, mankind has evolved to flirt—so why is it so hard for so many? It all comes down to the way we process the subtle and sophisticated signals people send during the act.

We talked to behavioral experts about what happens in our brains and bodies when we flirt. We can’t guarantee this information will improve your flirting skills, but we hope it’ll help you understand why that sexy wink you attempted the other night didn’t go over as planned.


One reason flirting can be so challenging—even terrifying—is that, as humans, we are inherently afraid of strangers. This fear is a leftover survival instinct from our days as hunters and gatherers. Thanks, evolution!

When we meet other humans, our amygdala—the part of our brain responsible for our body’s “fight-or-flight” response to perceived danger—kicks into high gear. We tense our jaws, furrow our brows, and enter into a state of high alert.

“There’s a biological distrust that animals have of strange animals,” explained David Givens, an anthropologist and director of the Center for Nonverbal Studies, a private, nonprofit research center in Spokane, Washington that studies human communication.

Unfortunately, the fear induced by the amygdala can be a problem for mating. That’s where flirting comes in. Its role is not just to help you pass time on the grocery line but to temper some of the effects of this fear—to show that we come in peace.

“When you have to get males and females close together to exchange genetic material, there are signs that have evolved to show safeness and interest,” Givens said, which curb that fear. “These are the signs and signals that make up our flirting, and they go way back some 500 million years.”

In other words, humans flirt, in part, to convey: “I’m harmless. I’m not trying to kill you or steal your food. I just want to hang out some more.” But this is why flirting can be tricky—at its core, it’s a fragile negotiation. Don’t show enough interest, you may not get noticed. Show too much interest, the other human remains fearful.

The brain’s amygdala is part of a larger system called the “limbic system”—sometimes referred to as the “limbic reward system”—which controls not only fear, but pleasure. It also drives our desires for things like food, sex, and love—and it’s highly involved in addiction.

When we’re attracted to someone, as we move past the fear of stranger danger, other parts of the limbic system kick in. Our brain releases dopamine, a feel-good hormone and neurotransmitter associated with euphoria, to encourage us to keep going.

Suddenly, the pleasure we feel (and crave) outweighs the fear, and our bodies start sending nonverbal messages to signal our interest—and seek reward—from our flirting partner.

But this can be easier said than done. “Flirting behaviors are all about maintaining an element of ambiguity,” said David Henningsen, a professor in the department of communication at Northern Illinois University, who has studied flirting techniques extensively.

That ambiguity is meant to keep flirting non-committal. That way, a person can easily exit a situation without hurting another person’s feelings or can protect him- or herself from being hurt. “The genius of flirting is that it’s a shield,” he told me.

The anterior cingulate cortex—the part of the brain that feels rejection—helps keep that shield up. It knows that getting turned down is a real possibility, which is why a little part of your brain still says proceed with caution. Indeed,

Flirting is a continuous balancing act between diving in, but not too far—which is why knowing and recognizing the signals is key to success.


Once humans go from “who the hell are you” fear to “hey, you’re kind of cute” flirting, the body becomes a vehicle for getting its point across.

“One of my favorite nonverbal cues is shoulder shrugging,” said Givens, who is also the author of the book Love Signals: A Practical Field Guide to the Body Language of Courtship. “In courtship, you’re showing a submissive stance by shrugging your shoulders—that lets the partner know you’re not going to bite.”

Other key signs of interest include talking with your palms up, which is seen as a friendly gesture (chimps do this, too); leaning in toward the person of interest; touching your hair; or the classic staring deeply into his or her eyes.

Not only does looking into someone’s eyes signal interest, but studies have shown that mutual staring can increase attraction. How? First, eye contact is received by the brain’s vision center. Next, the sensory impressions created travel to the hypothalamus, a region of the brain involved in sexual behavior. (One of its many jobs is to regulate hormones, including “love hormone” oxytocin.) This process can then lead to feelings of sexual arousal, according to work done by neuroscientist Simon LeVay.

That’s just one way the hypothalamus is involved in flirting. In times of uncertainty—for example, when you meet someone new you really like—it can also trigger the sympathetic nervous system, which in turn causes your heart to race, your palms to sweat, your blood pressure to rise, and your cheeks to flush. Clearly, not all natural responses to flirting are sexy, per se, but they can still be indicators of interest.

Another cue is mirroring (or “isopraxism,” in science speak), in which two people subconsciously make similar, if not identical, movements. Givens explains that when he’s observed people flirting in coffee shops and bars (also known as “field work”), slowly but surely, their bodies start to mimic each other, “because safe is same and same is safe.”

For example, both people will sip water at the same time, or lean to their right within seconds of each other, or rest a palm on their face in near unison. This mimicry is a sign of admiration, interest, and reassurance.

Movement in general can be a powerful device for connection, Givens explained. Humans are more attracted to moving bodies than static ones (think of watching someone dance versus stand). And mirror neurons fire both when we act and when we observe the same action by another. For example, if a woman in a coffee shop begins stroking her leg in plain view, you—the person watching—may feel like your leg is being stroked as well.

“The mirror neurons interpret that signal as you yourself delivering a touch,” he said. Depending on our state of mind, this can feel good and further the mating ritual—since actual touching is one of the final stages of courtship.


With all these nonverbal cues flying around, it can be easy to misinterpret the signals, especially since flirting is not always used for sex. Humans also flirt for attention, money (think of a waitress flirting for tips), to persuade someone to do something for us—or just for fun.

Flirting is very much a goal-oriented behavior, said Henningsen—and when that goal is something other than mating, problems can arise. “The biggest mistake people make, men in particular, is they will think it’s sexual when it really wasn’t,” he told me, “and that leads to awkward interactions.”

Why does this happen? Studies have shown that men tend to overestimate a woman’s interest in them, while females tend to underestimate interest. Sound like a recipe for disaster? It is. So why did we evolve this way?

According to Henningsen and other experts, one theory is that men evolved to pick up on sexual cues of interest and respond in hopes of procreating with as many females as possible. If our ancestors’ choice was to “try or not try,” only trying would lead to more sex and more offspring. And so casting a wide net became an evolutionary advantage.

Our female ancestors, meanwhile, didn’t gain anything by acting on every sexual advance thrown their way. Instead, it was in their best interest to maintain and secure a committed relationship, since human babies take so much time and energy to raise. Women’s advantage lies in being picky.

Today, a woman can use this knowledge to her benefit—knowing that a man is hanging onto to every single sexual cue—and flirt with absolutely no sexual attraction.


Flirting is a precarious ritual—a delicate balance between fear and attraction that is key to helping our brains and bodies decide if we want to pursue a sexual relationship.

But as a final thought, remember that it can also be done just for fun—and knowing that is key, said Henningsen. “In every study I’ve done, the strongest motive for flirting is that it’s for fun,” he told me.

So if you find that you’re too nervous to say something clever the next time you want to approach someone—don’t blame your lack of confidence, blame your sympathetic nervous system. And try to relax into it. Humans have been doing it for millennia—and you can, too.