What is Attraction?

Love—or Something—Was in the Air

When women breathe in androstadienone, an often-odorless testosterone derivative in male sweat, they give men higher attractiveness ratings than they would otherwise. After about 15 minutes of exposure, the chemical makes a woman subtly more attentive, aroused—and even happier— with effects continuing for up to an hour, finds a study led by Claire Wyart at the University of California at Berkeley. (In case you’re wondering, men vary in their androstadienone levels—and, no, the chemical doesn’t brainwash women into having sex or falling in love. It’s much more subtle than that.)

Your Body Said Something Irresistible

In an hour at a singles bar, average-looking women could be approached by up to four men, found Monica Moore in her study at the University of Missouri. What were these sirens doing? Making more than 35 body language gestures—smiles with eyebrows raised, short, darting glances, arm flexes, hair flicks, neck caresses, and other “displays.” Meanwhile, Moore found that a beauty who sits there doing nothing is unlikely to be approached at all. Only when a woman’s body language expresses some interest do men feel comfortable making a move.

Your Parents Were Yuppies

A person born to a couple in their 30s grows up to find older faces more attractive than does one with younger parents, finds a study from the University of Saint Andrews in Scotland. That is, college-aged women with “older” parents were likelier to find wrinkled, weathered faces attractive for either a fling or a marriage. The same was found for young men when considering a woman for a long-term relationship. (Take note: Only a man’s mother’s age, not his father’s, influenced his attraction to older women.)

You Wore Crimson and Rose

Like moths to a flame—that’s how attracted we all are to the color red. Wearing red increases a woman’s chances of being asked out—and of having her date splurge on her—finds a study from the University of Rochester. The simple explanation: ladies in red are perceived as more sexually receptive due to the color’s associations with fertility. Sure enough, the researchers found that single women who posted photos of themselves on online dating sites wearing crimson, scarlet, fuchsia, and other reddish hues—even on just a T-shirt— were more than two times likelier to be interested in casual sex than those wearing any other color of the rainbow. For men, the color red has an association with high-status, which may be why women give guys in, say, red jock straps or ties higher attractiveness ratings. Simply wearing the color may trigger a virtuous cycle: it encourages us to act sexier because we expect others to think we’re hotter (women) or more confident and powerful (men).

Your Limbal Rings Are Riveting

The eye’s limbal ring goes in the category of overlooked but not unseen. It’s the dark circle around the iris that enhances the whiteness and brightness of the sclera (the whites of the eyes). Researchers at the University of California at Irvine asked people to rate sets of faces that were identical except for the eyes—one had dark and distinct limbal rings and the other had none. The outcome? Whether male or female, the faces with prominent limbal rings were considered more attractive. The likely reason is that a dark, well-defined ring is a signal of youth and health—qualities that people seek in mates. It’s thickest and most prominent through the early 20s and fades—often becoming nonexistent—with age and medical conditions.

You Were the One Using the Pick-Up Line

Women are pickier than men, right? Not true, says a speed-dating study from Northwestern University. When men remained seated and women rotated around the room, approaching a new man at every table, the women acted more like guys—that is, they appeared to have lower standards. Regardless of gender, whoever makes the first move is less picky than the people they target, the researchers found. When we invest an effort, we’re more “into” the people we hit on than we’d be if they approached us first.

You Chose the Perfect Perfume

Your signature scent— whether it’s Chanel, Shalimar or patchouli—becomes you. Literally. Fragrances may amplify and advertise your unique genetic makeup to potential partners, finds a study from the Max Planck Institute in Germany. People who share the same variants of immune system (MHC) genes often preferred the same scents (rose oil, musk or vanilla, for instance). This suggests that particular scents work best with particular body chemistries—and that we know intuitively what fragrances smell best on us. Indeed, a recent Czech study found that when volunteers’ sweat was mixed with their preferred perfume (versus a random one), impartial noses gave the resulting mélange much higher ratings.

You Had Chemistry, on Top of Chemistry

We all know oral contraceptives are useful—for reducing flow and cramps and preventing unplanned pregnancies. The surprise is that the Pill may also lead to unintended romantic quandaries. A U.K. study found that women who were on oral contraceptives when they met their partners were, years later, likelier than non-users to be turned-off, sexually dissatisfied and eager to fantasize about an affair. But here’s the interesting part: They were also generally more satisfied with their partner’s (non-sexual) contributions, and therefore less likely to separate. The researchers explain: Under Pill-driven conditions of high-progesterone and low fertility, women go for relationship-worthy qualities such as wealth and intelligence more than high-testosterone traits (biceps and block jaws) that are associated with flings. Oral contraceptives may also lead women to reverse their usual preferences in male body odor. Once a woman goes off the Pill, her other instincts complicate the relationship.

Betty Boop Came Out at “Hi”

Whether she’s aware of it or not, the pitch of a woman’s voice increases a notch (becoming higher but not shrill) when she’s flirting, finds a study from McMaster University in Canada. Conveniently, men much prefer these high-pitched dulcet tones over deeper ones. A woman can strike her highest chords around ovulation, when she’s likeliest to conceive. Another coincidence: This happens to be the time of the month that men give female voices the highest attractiveness ratings.