Understanding The Science Of Attraction

Medically reviewed by Elizabeth Erban, LMFT, IMH-E
Updated April 22, 2024by BetterHelp Editorial Team

The sensation of attraction in those who experience it can feel powerful and mysterious, but researchers have learned some illuminating things about how it works. The feeling of being attracted to someone involves your physical senses, your hormones, your nerves, and even your immune system. It can be sparked by a wide variety of cues, from the shape of another person’s face to the particular way they smell. Keep reading for a more detailed look at what science can tell us about the factors that may draw two people who experience romantic and/or sexual attraction together.

Experiencing difficulties in your romantic life?

The science of attraction: The basics

To start, let’s take a closer look at what’s actually happening in your body when you feel that first rush of attraction to someone else. The initial surge of excitement appears to involve a complex balancing act between the sympathetic and parasympathetic nervous systems. The sympathetic system is the “fight-or-flight” mechanism, and it’s what makes your heart race and your pulse pound when you’re looking at someone you desire. 

Research suggests that a moderate amount of sympathetic nervous activity may be necessary for the initial stages of arousal, but that too much or too little can suppress desire. This might explain why watching a scary movie when you know you’re safe can be a fun date night, or why activities that make your heart race can increase feelings of attraction. The parasympathetic system, then, is more associated with relaxation and pleasure. It’s involved in many of the physical changes in the body during sex, such as genital swelling and releasing of sexual fluids.

The early stages of arousal also often cause your blood to pump faster and your pupils to dilate. They may increase your skin’s conductivity too, which is perhaps why attraction can feel so electric. Then, as two people become better acquainted and their intimacy deepens, dopamine-mediated pathways in their brains may become more active. These systems are associated with rewards, habit formation, and even addiction, and they may be what prompts people who are falling in love to obsess over their partners and feel a rush of pleasure just from being near them.

Specific factors involved in attraction

Extensive research has been done into why people are more attracted to some individuals than others. While there’s still plenty to learn, you can read on for an overview of some key research in this area.

The role of immediate first impressions

We’ve all seen cartoons or movies where a person spots someone they find good-looking and their jaw drops and eyes widen, conveying instant attraction. Though it doesn’t normally happen quite like this, research suggests that our brains do make very rapid judgments about who we find attractive. 

In a study conducted at Trinity College in Dublin, researchers briefly showed participants images of possible dating partners. Later, they were given the opportunity to actually interact with the people in the photos during a speed-dating event. Their snap judgments during the four seconds they spent looking at the photos turned out to be good predictors of who they would go on to click with in conversation.

Brain scans pointed to two areas that seemed critical for making these judgments about attractiveness. One is a structure called the paracingulate cortex, which appears to be involved in social evaluation. It tended to light up when viewing photos of people that the majority of participants rated as attractive. Another area, the rostromedial prefrontal cortex, seemed to activate more for people who weren’t attractive to the majority but sparked a particular viewer’s interest.

The role of eye contact

While a quick glance at another person’s face may be enough to spark attraction, a long, soulful gaze may be important for deepening it. Prolonged eye contact can provoke an experience of intimacy and vulnerability that may be important in forming interpersonal bonds. In a pair of studies conducted in the 1980s, one found that those who exchanged a mutual, unbroken gaze with a participant they didn’t know for two minutes reported a “greater liking” of them than any of the other subjects. The other indicated that existing romantic partners who were assigned the same task reported a “significant increase in feelings of passionate love, dispositional love, and liking for their partner.” 

In a related study, researcher Arthur Aron developed a series of 36 increasingly intimate questions that a pair of strangers could ask one another to generate a sense of closeness, which they were to follow by four minutes of prolonged, silent eye contact. His goal was to figure out how to craft the sense of intimacy that can make strangers fall in love. In this initial study, participants left with more positive feelings for each other—and one pair famously went on to get married. 


The role of scents

There seems to be a lot more to the science of attraction than visual appeal; smell appears to be another important piece of the puzzle.

Research suggests that, while humans were long considered to have an underdeveloped sense of smell compared to many creatures in the animal kingdom, pheromones may actually play “an important role in the behavioral and reproduction biology of humans.”

Pheromones are chemicals humans naturally secrete that may serve as a form of “olfactory communication”, especially when it comes to attraction. 

For instance, androstadienone, a compound present in male sweat, seemed to improve the mood, emotional focus, and sexual arousal of heterosexual women in some experiments. Meanwhile, chemicals called copulins that are found in vaginal secretions seem to provoke higher ratings of female attractiveness to heterosexual males. Copulins also caused men to rate themselves as more attractive to women, suggesting that they might play a role as confidence boosters.

Another potential component of scent-based attraction may be the immune system. Some studies have indicated that heterosexual women may be more likely to be attracted to the body odor of men whose genes for certain types of immune cells are different from their own. There could be an evolutionary advantage in this behavior, because a child with more diversity in their immune system may be able to fight off a greater variety of diseases.

Attraction and fertility

From an evolutionary perspective, all sexual behavior is aimed at producing offspring. That may be why studies have found that people of multiple genders find women’s faces more attractive when they’re ovulating. There appear to be subtle changes in appearance associated with this part of the menstrual cycle that can be detected even in photos. Another experiment showed a similar effect on body odor, with men preferring the smell of women’s clothes during the most fertile part of their cycles. Even women’s voices may shift during ovulation, sounding more attractive to heterosexual men. 

Similarly, experiments suggest that women’s preferences for more masculine facial shapes and their corresponding body odors change with their cycle. Heterosexual women might be more likely to feel attraction in response to symmetrical faces and masculine-coded looks when their fertility is at its peak. However, these preferences appeared to be strongest when considering certain people for short-term relationships; fertility didn’t appear to have an effect on perceptions of possible long-term partners.

If the menstrual cycle can affect perceptions of attractiveness, however, can birth control pills do the same? There is some evidence that by changing the body chemistry of ovulation and menstruation, hormonal birth control can affect a person’s preferences for romantic partners. Scientific evidence on the topic includes:

  • Its effects on facial feature selection: The findings of a study of 170 heterosexual couples revealed that women taking birth control pills were more likely to pair up with men whose faces were less stereotypically masculine

  • Its effects on selection for body odor: Other experiments found that heterosexual women’s preferences for male body odor depended on whether they were using hormonal contraception. 

  • Its effects on sexual satisfaction: There’s even evidence suggesting that some women who start or stop using birth control pills during a relationship could be more likely to become less sexually satisfied and less attracted to their current partner. 

Experiencing difficulties in your romantic life?

Getting support for your romantic life

If you’re facing challenges in dating or in your romantic relationships, you may benefit from professional support. Many people find that meeting with a therapist is a helpful way to uncover patterns of attraction, sort through emotions related to a partner, and develop useful dating and relationship skills such as boundary setting and conflict resolution. A cognitive behavioral therapist in particular can also help you unearth any distorted thoughts you may have about your own attractiveness or ability to form relationships and shift them in a healthier direction for better potential outcomes.

If the thought of meeting with a provider in person for support with your romantic life seems awkward or intimidating, you might consider seeking guidance virtually instead. With a virtual therapy platform like BetterHelp, you can get matched with a licensed provider who you can meet with via phone, video call, and/or in-app messaging from the comfort of your home. Since a comprehensive analysis of past studies including more than 10,000 participants concluded that there was “no difference in effectiveness” between face-to-face and web-based counseling, you can feel confident in whichever method you choose.


Romantic and sexual attraction may involve countless subtle factors, from the sound of a person’s voice to the makeup of their immune system. The initial spark can happen in a matter of seconds, while lasting intimacy and compatibility take more time to develop.
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