If this color reminds you instantly of love and lust, thank your animal instincts. Much as a baboon’s red bottom becomes redder to encourage mating in the animal kingdom, a 2010 study in the European Journal of Social Psychology reported that men rated a “moderately attractive” woman more attractive if she happened to be wearing a red top. Ditto for women—another study found 288 female undergrads viewed men in red as more powerful (and therefore more sexually desirable). And when anthropologists at England’s University of Durham studied the 2004 Summer Olympics in Athens, Greece, they found that when sporting opponents were equally matched in fitness and skill, whoever was wearing the red jersey was more likely to win the event.
The flip side of this is that red can have negative effects. “Red releases adrenalin into the bloodstream,” according to McLeod, which isn’t always good: In 2007, researchers at the University of Rochester and the University of Munich found people shown red prior to writing IQ tests performed worse. The researchers hypothesized that red is “associated with the danger of failure in achievement contexts” and therefore causes anxiety.