Thank goodness Victoria University’s $60,000 “Eyelink 1000” eye-tracking device was available recently to psychology PhD student Barnaby Dixson, for now we have more clarity on what, exactly, men think of women’s breasts.

Dixson recruited men to look at images of naked images of women that were digitally altered to increase or decrease the size of her bust and the color of her areola (the ring around the nipples). In keeping with evolutionary theory and previous experiments on men’s breast size preferences, Dixson hypothesized that guys would gaze longer at larger breasts and prefer light areolae. Fair to light pigmented areolae and nipples would be considered sexier, he reasoned, because these hormonally-sensitive features darken with pregnancy and with age. He also asked the guys to rate the attractiveness of each photo.

But the results weren’t exactly as expected.

Turns out that men did indeed rate women with medium-sized and large breasts as more attractive than women with small breasts. But variation in breast size did not affect their eye movements — they were just as likely to fixate on small breasts as large ones, and for the same number of times.

And the nipple data was even more shocking. The first thing men fixed their gaze on was women’s areolae. And while they fixed their gaze just as often and as long on pale nipples as dark ones, the majority expressed a distinct preference for dark areolae. Dark nipples appear to play a significant role in men’s judgments of women’s attractiveness.

Like large breasts, Dixson reasoned, dark areolae suggest sexual maturity. Yes, older and pregnant women have darker nipples than younger women, but those pigment changes also come from hormones that suggest fertility — high levels of estrogen and progesterone.

Is a successful line of nipple and areolae blush in this PhD student’s future?