Scientific studies reveal clues—some surprising—on what makes us attractive to potential mates. You’re born with some traits such as good looks or—gasp!—the right smell. These are characteristics you can revise to some degree. Think cosmetics or perfume. Other traits that signal attractiveness can be even easier to change. Making yourself more attractive doesn’t necessarily require running to the makeup counter or splurging on the latest fashion.

Attractiveness is the sum of many different traits, both physical and personality. Appearances do count in this day of “swipe right, switch left.” Research says we seem a lot less attractive when we aren’t getting enough sleep. One study found the sleep-deprived appeared not only less attractive but also less healthy and sadder. Looking mean or too proud can be turnoffs. Showing contractive body language such as crossing arms or hunching shoulders can make you less attractive.

Stress can make you unattractive. Women with high levels of the stress hormone cortisol were perceived by heterosexual men as less attractive in one recent study. Researchers say that’s possibly because lower stress and lower cortisol levels indicate health and fertility.

And it’s not just appearances that matter. Personality and character count. A study asked participants to rate photos of potential mates on whether they looked either intelligent or unintelligent, dependent or independent, and honest or dishonest. The only trait out of the three that participants judged as having a substantial effect on attractiveness and liking turned out to be honesty.

Even smell comes into play. Researchers have found that the more similar their smell, the less attracted the participants were to their partners. At the same time, however, studies have also found that we avoid partners who smell too different from us.

Science seems to have narrowed the most universally attractive personality traits down to four, and luck is on our side. These are four trails that we can all improve with some honest effort.

Positive Attitude

You can learn to be a positive thinker, and the rewards will carry over to other aspects of your life in addition to romance. Those who are more optimistic tend to be healthier both physically and mentally. They are more successful at work, and they even tend to live longer lives.

Balanced Extroversion

Psychologist Adrian Furnham, PhD, for Psychology Today says extroverts who are outgoing and easily conversational enjoy “big social networks, a history of good relationships, an inclination to explore opportunities, and dis-positional happiness.” They are also more likely to find generally more “mating success” with more sexual partners and more offspring.


Confidence is a very attractive personality trait. Potential partners say self-assured people are more authentic as well socially magnetic, according to one to an Arizona State University study.

Sense of Humor

A sense of humor ranks among the top five qualities people look for in a partner. Alas, an average sense of humor or no sense of humor was found in a study to be significantly less attractive than a great sense of humor.

Read More: to 5 Simple Ways to Trick Yourself into Being More Positive.