27 September 2006
Beauty Is NOT In The Brain Of The Beholder
by Kate Melville

The phrase "easy on the eye" may also mean that an image is easy on the mind, as it seems that judgments of attractiveness depend on ease of mental processing. At least, that what experiments led by Piotr Winkielman, of the University of California, San Diego, suggest. "What you like is a function of what your mind has been trained on," Winkielman explained. "A stimulus becomes attractive if it falls into the average of what you've seen and is therefore simple for your brain to process. In our experiments, we show that we can make an arbitrary pattern likeable just by preparing the mind to recognize it quickly."

The new research, appearing in Psychological Science, follows up on earlier studies establishing that prototypical images are rated as more beautiful or appealing than variations of the same thing. The phenomenon - sometimes known as the "beauty-in-averageness effect" - was most dramatically demonstrated by Judith Langlois' lab, at the University of Texas at Austin, in the 1990s, when people scored computer composites of 16 faces higher than any of the individual component faces.

Since then, other studies have demonstrated that humans have similar preferences for prototypes in a wide variety of other categories, including dogs, birds, fish, cars and even watches. A popular explanation has been an evolutionary, sexual-selection one that goes something like this: Like symmetry (another reliable predictor of attractiveness), prototypicality signals health and fitness - unusually protuberant eyes might be a clue to disease, for example - and so is a kind of shorthand for the value of a potential mate. While such an explanation makes sense when it comes to human faces, it sounds ridiculous when applied to inanimate objects, or animals, which we are not assessing for reproductive purposes.

So, working with co-researchers from the University of Otago, New Zealand, and the University of Denver, Winkielman decided to investigate whether there wasn't a more basic mechanism at work. It's well-known that prototypes are attractive, the researchers reasoned. It's also well-known that prototypes are easy for the brain to process (as measured by the speed with which people are able to categorize what it is they're looking at). So, could it be, they wondered, that prototypes are beautiful because they're easy to process?

To assess their hypothesis, the researchers designed an experiment using random-dot and geometric patterns. "We wanted to use stimuli that were free of reproductive content," Winkielman explained. The researchers first "prepared" participants' brains to perceive a prototype and then asked them to categorize different degrees of variations around that same prototype and rate their appeal. "As predicted, participants categorized patterns more quickly and judged them as more attractive when the patterns were closer to their respective prototypes," said Winkielman. "Critically, the less time it took participants to classify a pattern, the more attractive they judged it."

Interestingly, when ease-of-processing was controlled (the categorization speed was factored out of the equation), much of the relationship between closeness to prototype and attractiveness disappeared.

The researchers conducted another experiment (also with abstract, random-dot images) with electrode measurements at cheek and brow muscles (to detect the formation of incipient smiles or frowns), and again confirmed a genuine positive response to those images that were closest to prototype. "It seems you don't need to postulate an unconscious calculator of mate value or any other 'programmed-brain' argument to explain why prototypical images are more attractive," Winkielman said. "The mental mechanism appears to be extremely simple: facilitate processing of certain objects and they ring a louder bell. This explanation accounts for cultural differences in beauty - and historical differences in beauty as well - because beauty basically depends on what you've been exposed to and what is therefore easy on your mind."

Source: University of California - San Diego