Cognitive Daily

Is beauty a universal standard? Or is it in the eye of the beholder? Some research on attractiveness, including some we've discussed on CogDaily, suggests that "average" faces are the most attractive, and that most people agree on what makes a pretty face.

But Johannes Hönekopp has recently questioned the statistics behind these studies. Consider a hypothetical study that asks participants to rate the attractiveness of Leonardo DiCaprio and George Clooney on a scale of 1 to 10. From one perspective, nearly all judges might give both faces extremely high marks. Taken from this point of view, a researcher could argue that there is universal agreement that DiCaprio and Clooney are both attractive. But a closer look at the data would show that some judges consistently prefer DiCaprio over Clooney, while others consistently prefer Clooney. Can we really say that everyone has the same conception of attractiveness?

Hönekopp designed a set of three experiments to explore the relationship between individual preference and group preference (he calls these "private taste" and "group taste"). Each experiment was conducted in a similar manner: volunteers were shown photos of several dozen faces and asked to rate them on a scale of 1 to 7. Then one week later they returned to rate the same photos again (this was done to ensure that individual preferences were relatively consistent).

In Experiment 1, the faces and judges were college-age students. In Experiment 2, Hönekopp wanted a more diverse group, so this time faces and judges were equally distributed among Caucasians, Blacks, and Asians. In experiment three, faces and judges were evenly divided among men and women. In all the experiments, there was a significant correlation between the ratings of all the judges. However, as Hönekopp has argued, this isn't in itself an indication that there are universal standards for attractiveness.

To further analyze the data, Hönekopp devised a new statistic, which he called the beholder index. In its simplest form, the beholder index is expressed like this:

The value of this ratio can range from zero to one -- a value of 1 would indicate that all variation in attractiveness ratings are due to individual differences, while a value of 0 would indicate all variation is due to group differences. Next, he divided responses into two groups: the middle-ranked faces (those with rankings closest to average), and the extreme-ranked faces: the top quarter and bottom quarter of the rankings). Here's what the beholder index looks like for these groups:

Because this is a new statistic, there's no real way to establish statistical significance, but the trend that's shown here, with three very different samples and sets of judges, is quite clear: when there is a large difference between the faces being evaluated, then the tastes of the group outweigh individual differences (nearly everyone will rank George Clooney as more attractive than Osama Bin Laden). But when the difference is small, then individual preferences of judges become much more important (there is little agreement over whether Fred Astaire is more attractive than Gene Kelley).

Hönekopp, J. (2006). Once More: Is beauty in the eye of the beholder? Relative contributions of private and shared taste to judgments of facial attractiveness. Journal of Experimental Psychology: Human Perception and Performance 32(2), 199-209.