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Natural selection and thin slicing

In the Reith Lectures 2003, acclaimed neuroscientist V.S Ramachandran first talked about art and the brain and something he called 'artistic universals', which he says are principles of art that exhibit similar neurological activity in the brain across different cultures. He thinks that there are around 10 such artistic universals (see website). One among them is called the 'Peak Shift' universal. He explains this wonderfully using a bit of research finding on the feeding habits of newly born seagull chicks:

As soon as the herring-gull chick hatches, it looks at its mother. The mother has a long yellow beak with a red spot on it. And the chick starts pecking at the red spot, begging for food. The mother then regurgitates half-digested food into the chick's gaping mouth, the chick swallows the food and is happy. Then Tinbergen [the researcher] asked himself: "How does the chick know as soon as it's hatched who's mother? Why doesn't it beg for food from a person who is passing by or a pig?"

And he found that you don't need a mother.

You can take a dead seagull, pluck its beak away and wave the disembodied beak in front of the chick and the chick will beg just as much for food, pecking at this disembodied beak. And you say: "Well that's kind of stupid - why does the chick confuse the scientist waving a beak for a mother seagull?"

Well the answer again is it's not stupid at all. Actually if you think about it, the goal of vision is to do as little processing or computation as you need to do for the job on hand, in this case for recognizing mother. And through millions of years of evolution, the chick has acquired the wisdom that the only time it will see this long thing with a red spot is when there's a mother attached to it. After all it is never going to see in nature a mutant pig with a beak or a malicious ethologist waving a beak in front of it. So it can take advantage of the statistical redundancy in nature and say: "Long yellow thing with a red spot IS mother. Let me forget about everything else and I'll simplify the processing and save a lot of computational labour by just looking for that."

That's fine. But what Tinbergen found next is that you don't need even a beak. He took a long yellow stick with three red stripes, which doesn't look anything like a beak - and that's important. And he waved it in front of the chicks and the chicks go berserk. They actually peck at this long thing with the three red stripes more than they would for a real beak. They prefer it to a real beak - even though it doesn't resemble a beak. It's as though he has stumbled on a superbeak or what I call an ultrabeak.

From the above research it seems that evolution naturally opts for 'thin-slicing' or thin-slicing is nothing but nature’s way of indicating that it has gained expertise in that area.

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