Most of us understand or at least appreciate the concept of “grouping” in art e.g. showing reoccurring patterns or colors. I recently came across an interesting article that offers a theory as to why man evolved to appreciate aesthetic grouping. First the author defines the grouping concept:

Grouping is a well-known law frequently used by both artists and fashion designers. If you look at the classical Renaissance painting in figure 5, you will notice how the same azure blue color repeats all over the canvas — the sky, the robes, and the water. And the same tint of brown is used for clothes, skin, soil, etc. The artist uses a limited set of colors rather than an enormous range of colors.
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The same holds for fashion. When you go to Nordstrom’s to buy a red skirt the salesgirl will advise you to buy a red scarf and a red belt to go with it…. what’s all this really about? Is there a logical reason for doing this? Is it just marketing and hype, or is it telling you something fundamental about the brain? This is the why question.

Yes, why? The question is enough to drive one mad.

…think of one of your arboreal ancestors trying to spot a lion hidden behind a screen of green splotches (a tree branch in front of it). What’s visible is only several yellow splotches — lion fragments. But the brain “says” (in effect): “What’s the likelihood that all these fragments are exactly the same color by coincidence? Zero. So they probably belong to one object. So let me glue them together to see what it is. Oops! It’s a lion — let me run!” This seemingly esoteric ability to group splotches may have made all the difference between life and death.

Earlier in the article, the author makes an inadvertently funny comment.

Chennai (Madras), the city in Southern India where I was born, dates back to the first millennium B.C. I often return to it as a visiting professor at the Institute of Neurology to work on patients with stroke, with phantom limbs following amputation, or a sensory loss caused by leprosy. During one three-month visit, we were going through a dry spell; there weren’t many patients to see.

Yes, it’s really a shame that stroke, phantom limb pain and leprosy are on the decline.