When surveyed, most people say they get tattoos or unconventional piercings to express individuality. But could something more psychologically primal be afoot? Researchers at the University of Wroclaw in Poland measured about 200 men and women–half of them inked or pierced in places other than their earlobes–for body symmetry, or how similar their right and left sides are. (More similarity indicates genetic health and is associated with sexual attractiveness.)
Among the research subjects, men with bodily decorations exhibited greater symmetry than those without, whereas no differences emerged in women. Because people who are less symmetric did not opt more often for tattoos and piercings, researchers rejected one widely held hypothesis that suggested people use physical graffiti to hide or distract from imperfections in their appearance.