10 Science-Backed Reasons for Sexual Attraction

Updated: May 12, 2021

Here's all the science behind the reasons you swoon: Learn the laws of attraction



When you’re describing how good-looking someone is, chances are you don’t say, “She/he is so symmetrical!” But multiple studies have revealed that a person’s “symmetry”—basically, how closely both sides of their face/body match—plays a big part in how attractive we find them. There may be a scientific reason for that as people who had lower levels of oxidative stress in their body also had more symmetrical features, meaning symmetrical folks may actually be healthier, according to a study published in the journal Animal Behavior.

In the study, ten measurements were taken of the men to determine their symmetry—things as specific as ear height and finger length. Then they were tested and quizzed for indicators of oxidative stress. Finally, a group of women was asked to rate images of the men’s bodies and faces for physical attractiveness. Men with more symmetrical bodies had lower levels and were rated as more attractive. Of course, no one is perfectly symmetrical so make sure you know these 12 things sex therapists won’t tell you.

Feet stepping on a bathroom scale

The perfect body mass index

Your body mass index (BMI) refers to the relationship between your height and your weight. Women who fall on the low end, below what is considered healthy, are considered the most attractive, according to a study published in PLoS One. For men, the results were more forgiving, with maximum attractiveness correlating with the healthy BMI range, they found. Don’t get too hung up on this one factor, though, check out the sex myths that everyone thinks are true but needs to ignore.

a woman's legs reclining on a beach

Long legs (but not too long) 

Both men and women preferred people with legs slightly longer than average, according to a 2019 study published in The Journal of Cross-Cultural Psychology. Researchers surveyed people of both genders in 27 different nations and found that legs that were excessively short or long were seen as unattractive, regardless of culture.

Man in a blue shirt smiling

Face shape

Certain facial features are considered most attractive—in men, it’s a strong jawline and in women, it’s large wide-set eyes. Both are examples of facial dimorphism—how men’s and women’s faces differ. This means the most attractive people are those who skew more masculine (in men) or feminine (in women), according to a study published in PLoS One. Both genders also preferred mates who showed signs of physical maturity. Try one of these 9 tricks to improve your sex life in just one day!

close up of a scar on skin

Facial scars (in men)

Men, are you self-conscious about a small facial scar? Don’t be: some facial scarring makes men more attractive to women, according to a study published in Personality and Individual Differences. The scars might be appealing as they are evidence that a man is leading an active or exciting life. There is a catch, however: The scars only increased attraction when the women were interested in short-term relationships. Both genders preferred unblemished faces when looking for a life partner.

woman with brunette hair looking into a man's eyes

A “sexy” voice

It’s all about the hormones: A lower voice in men is associated with more testosterone, while a higher voice in women is seen as more stereotypically “feminine.” However, it’s not just about pitch. One of the biggest predictors of attraction was a voice that sounded similar to their own, particularly in dialect and accent, according to a study published in PLoS One. The researchers suggest this is because we strongly prefer people who are like us and come from the same community. Besides a sexy voice, here are 31 more tricks that are proven to give your sex drive a boost.

man and a woman resting on their elbows in the sun

Your genetics match

Ever heard that married couples look alike? This common joke might have a basis in truth. In the past, people overwhelmingly married people of common ancestry, and that trend has had lasting effects. We’re drawn to things that are familiar—on a genetic level—because they make us feel more comfortable, according to a study published in Human Nature.

a person opening a car door

Altruistic behavior

It’s not just about looks—our tendency to be drawn to attractive personalities has a basis in science as well.  People were sexually attracted to those they saw doing altruistic acts, like helping a child, according to a study published in The British Journal of Psychology. The attraction was doubly strong when they also found the person physically hot. Make sure you know these 25 sex mistakes you never realized you were making until now and how to fix them.

Asian couple having fun on the beach of tropical Bali island, Indonesia.
Artem Beliaikin/Shutterstock

They’re interesting

This might seem like a no-brainer but we are naturally attracted to people with brains, according to a study published in Intelligence. Both genders reported that “being smart” was an important characteristic in a mate with some even saying that intelligence was a sexual turn-on, they reported.

Beautiful fun happy smiling African American couple laying in grass


In a study by Cornell University, a group of people rated their ideal traits for long-term partners, and the overwhelming winner was fidelity. Faithfulness and trustworthiness ranked as extremely important to both men and women. “Good parenting, devotion, and sexual fidelity—that’s what people say they’re looking for in a long-term relationship,” says Stephen Emlen, PhD, the lead author of the study. And for couples who want to grow old together, the advice? Have more sex. Having sex at least once a week seems to increase longevity.