Spotting a Fake Smile
At least one good thing comes from a breakup: a better fake-smile detector. Social psychologist Michael Bernstein and his colleagues at Miami University found that people who felt rejected were better at discriminating between fake and real smiles. Researchers believe that a true grin indicates real emotions, such as cooperation, because some of the muscles we use—the ones around the eyes—are not under our conscious control. Our ancestors needed to be accepted in a group to survive, Bernstein says, so an outsider would not want to waste energy by acting on a fake reaction—or to miss a real opportunity to be included. —Rachel Mahan

Men Who Can Move
Most women agree that a man who can dance is attractive—and a recent study helps to explain why. Men who were exposed to higher levels of testosterone in the womb are judged by women to be better dancers. Peter Lovatt of the University of Hertfordshire in England found that the coordination and complexity of a man’s dancing, as well as the size of his movements, affect how attractive, masculine and dominant he appears to women. “We know that testosterone has an impact on physical characteristics,” Lovatt says. “It might be the case that higher-testosterone men have greater control over their bodies.” Dancing joins athleticism, musical ability and facial symmetry on a growing list of traits that increase a man’s attractiveness and are associated with prenatal testosterone levels. —Clara Moskowitz

Borrowed Identity
Cloaking oneself in a new identity—even for only a few minutes—can disrupt long-established patterns of behavior, new research suggests. Stanford University psychologists staged an online game in which players represented by on-screen avatars competed to solve a series of math problems. Subjects’ real gender didn’t affect their scores, but those who were arbitrarily assigned to a female avatar and who competed against two male avatars performed worse and gave up on difficult problems more quickly than did those who were assigned a male avatar and whose opponents were female. A large body of work shows that when women are reminded of their gender, their math performance suffers—but this study is the first to suggest that the effect of identity may not be tied to a lifetime of experiences. —Siri Carpenter

Speaking of Race
White people often avoid mentioning race because they fear that even noticing skin color might somehow make them appear racist, but two new studies from psychologists at Tufts and Harvard universities show that such “strategic colorblindness” can backfire. White participants studied a batch of photographs, then tried to deduce, as quickly as possible, which picture a black partner was holding by asking questions about each one in succession. Asking whether the person pictured was black or white would have sped up their performance, yet subjects—adults in one study and children as young as age 10 in the other—rarely mentioned race unless their partner did so first. Black observers who watched the recorded interactions perceived whites who avoided talking about race as more prejudiced than the intrepid few who acknowledged skin color. And blacks who watched silent video clips of the interactions even rated whites who avoided mentioning race as having more unfriendly nonverbal behavior. —Siri Carpenter

Marrying Mom?
A new study suggests that we prefer mates who resemble our opposite-sex parent. A Hungarian team found correlations of facial proportions between men and their partner’s father and between women and their partner’s mother. The findings support a “sexual imprinting” hypothesis: children shape a mental template of their opposite-sex parent and search for a partner who looks like it. —Nicole Branan