You have Beautiful Eyes, Hundreds of Them!

What do people look for in a partner? Many of us would love to know what aspects of our appearance are of most interest to potential mates. Well, we could start by posing the question 'What do people look at in a partner?' After all, what the eye does not see, the heart does not grieve over or in this case throb for.

Avian Eyetracking Shows Peahens Checking Out Males' Train Feathers
This is one of those research questions, however, where straightforward questionnaire data are likely to raise suspicions. How many people are going to admit that they look straight at someone's buttocks or cleavage? Eyetracking, on the other hand, can reveal a great deal about what people attend to, and has delivered such edifying conclusions as: Men seem to like to assess each other's crotches [1]; women check each other out as much as they do men [2]; and men look longer at larger breasts (even when controlling for the larger area of the visual field they occupy) [3].

Picture reproduced with permission from Yorzinski et al, J Exp Biol, 2013

A recent novelty, however, is the application of eyetracking to the romantic interests of birds. And no better bird to begin with than the peacock, famous for its eye-catching train of iridescent feathers, rattled in mating displays. Of course, in the animal kingdom it tends to be the women who do the ogling, so a recent study tracked peahens' eye movements while the males strutted their stuff [4].
The peahens were not especially impressed, spending less than a third of their time even looking at the male at all. Nor were they interested in everything he had to offer. The upper train, where most of the eyes are located, was of relatively little interest. Instead, the females' gaze lingered on the lower train, which they scanned from side to side in a way that suggests they were assessing its symmetry, an important feature in sexual selection [5].
So how can we make sure our next date results in love at first saccade? The authors offer a somewhat disheartening speculation. Briefer viewing times may indicate simply that a trait is much easier to assess. Peahens may look less at train eyes simply because it is very easy to see whether a male has fewer than required, and he may then be rejected without further ado [6]

[1] http://bit.ly/NCem7I
[2] Rupp and Wallen, Horm Behav, 2007
[3] Gervais et al, Sex Roles, 2013
[4] Yorzinski et al, J Exp Biol, 2013
[5] Moller and Thornhill, Amer Nat, 1998
[6] Dakin and Montgomerie, Anim Behav, 2011

by Luke Tudge,
This article originally appeared 2014 in CNS Volume 7, Issue 2, Neuroscience of Love