There is a lot more to the human eye than just seeing. For example, research shows (white) blue-eyed children to be more behaviorally inhibited than their brown-eyed counterparts; among stuttering children, those with blue eyes are more severely disfluent in their speech; and there have been studies in the past which attempted to use eye-color as a medicinal prognostic factor. (Eye color has even been used to predict alcohol use).
Given the type of research results mentioned above you might not be surprised if I tell you now that a study - soon to appear in the Journal of Personality and Individual Differences - has detected that men with brown eyes are perceived as significantly more dominant than their blue-eyed peers. However, there is more to the finding than ...well...first reaches the eye:
For their study, a team of Czech researchers, took similar (neutral, non-smiling, no make-up, etc.) profile pictures of 40 men and 40 women between 19 to 26 years of age. Then they asked a group of 62 raters -31 of them male - to judge the photographs for perceived dominance (as well as attractiveness) on a simple 10-point scale.
As mentioned already, brown-eyed males were perceived as more dominant, but it is what followed next, that is more interesting: To better understand what was driving the observed effect, the researchers now used photo-editing software to change the eye-color in all pictures from blue to brown and vice versa. After having done so, they repeated the experiment with a new group of raters, but - somewhat surprisingly - the original dominance ratings remained relatively unaffected. Although eye-color was a highly significant predictor of perceived dominance in the first rating session, switching eye-colors for all pictures did not significantly affect whose pictures were perceived as dominant and whose weren't.
So what is happening here? Evidently - and additional morphological research by the same research team supports this - eye color correlates with other facial features that raters use to judge dominance. For example, brown-eyed men in the above study had broader chins, thicker eye-brows which are closer together, and larger noses; all of which may be viewed as the actual drivers of higher dominance ratings. But yet there is more to learn here, since we should still want to know how this link between eye color and dominance signaling features comes about:
Is it simply that there is a strong genetic link between features that signal dominance and eye color? Unlikely, say the authors, since
"it is not easy to explain how iris color, which is determined mostly by one or a few genes, can correlate with physiognomic dominance/submissiveness, which is determined by a combination of several independent morphological traits. Theoretically,the allele for brown eyes should ‘‘move" from ‘‘submissive physiognomy genotype" to ‘‘dominant physiognomy genotype"and back again from generation to generation due to genetic recombination and segregation."
In other words, if eye color sits on only a few closely linked genes, and all the other features sit widely dispersed on a large number of independent genes, it is unlikely that they should all be passed on together; which would be necessary for the eye-color-dominance link to be sustained over successive generations.
Instead of a genetic interpretation then, the authors offer this interesting alternative: Social feedback.
"based on the presumption that blue and brown-eyed subjects are treated differently within their social surroundings, e.g. by their parents and peers [...]early social experience may have been literally ‘inscribed' into their faces, preserved until adulthood, and finally [may bring] on the perception of higher submissiveness."
The authors argue that, since children usually have blue eyes before their definite iris color develops during the first years of their life, it is plausible that blue eyed children receive "child-treatment" for a longer period of time than brown-eyed children. Being treated as a child for longer, makes people behave as a child for longer, makes them appear -even morphologically- more childlike in adulthood. The authors then continue to link this hypothesis to other research in this area, which I guess I would have to research more to reasonably comment on.
However, I will say, that I am really pleased by this study. Not because of the finding so much, but rather by it's intriguing (statistical/conceptual) beauty: First eye-color shows up big as a major predictor of dominance, then fades into the background as being a mere statistical correlate; a fake if you will. But then, at the end - if the social feedback hypothesis is correct - it is indeed eye-color that was responsible for everything all along. In my eyes, that is true Hollywood stuff.
[BTW: If you're wondering why I have pictures of blue eyes and not brown eyes in this post: It's not as easy to find a nice close up of a male brown eye on google...surprising]
Main Reference: Kleisner, K., Kočnar, T., Rubešová, A., & Flegr, J. (2010) Eye color predicts but does not directly influence perceived dominance in men. Personality and Individual Differences, 49(1), 59-64. DOI: 10.1016/j.paid.2010.03.011