The Science of Makeup

“The maintenance of youthful features and the exaggeration of female typical traits can be found in almost every culture,” says Dr. Bernhard Fink, a professor at the University of Göttingen who studies the evolutionary psychology of human mate preferences. Makeup works because it exaggerates (or completely fabricates) our natural signs of youth, fertility and sexual availability, thus making a woman seem more appealing. In other words, it works because it’s a darn good lie.

MORE: What Makes a Face Beautiful?

Studies have shown that women's faces are more attractive to both sexes near ovulation, when they’re most fertile. During this time, the relative concentration of the hormone estrogen rises in comparison to progesterone. This hormonal shift enhances vascular blood flow under the skin's surface, which has a few side effects: Women near ovulation report that they're more easily turned on and have more interest in sex. But this increase in blood flow also leads to visible signals—pinker cheeks and redder lips. Thus by putting on reddening lipstick, we accentuate a natural signal of fertility.

On top of that, blood flow also increases during arousal, so those red lips and pink cheeks are not only implying that her body is ready to have a baby, they're also saying that she’s interested in having that baby with you, the man she’s talking to right now, which of course is bound to draw attention from potential suitors.

Eye makeup and lipstick work synergistically to make a face appear more feminine. “Women tend to be naturally darker around their eyes and mouths than men of the same skin tone. When women use cosmetics to darken the eyes and lips, they are exaggerating this sex difference to make the face appear more feminine,” explains Dr. Richard Russell, an Assistant Professor of Psychology at Gettysburg College.

Courtesy of Dr. Richard RussellAn androgynous face with different levels of contrast. Perception 38, 1211–1219.

The key, Russell has found, is contrast. The darker the facial features in relation to the skin tone, the more feminine a face appears. His research has shown that this phenomenon is so important in distinguishing gender that the exact same face can be perceived as either male or female depending on the level of contrast.

In Russell's study, two near-identical faces were made by blending male and female faces. The only difference between the two was that one face had a lighter skin tone, thus creating more contrast. Most subjects thought the face with less contrast was male and the one with more contrast was female even though they had the exact same eyes, nose and mouth! Russell also found that when you digitally darken the eyes or the lips of a woman’s face, it becomes more attractive, while the opposite is true for a man’s.