When my youngest daughter, Sofia, was three years old, I asked her what makes us think. She pointed to her head and said: “My brain.” I then asked her whether other animals have brains, starting with dogs and monkeys and then birds and fish. She said yes. When I asked her about the ant that was crawling in front of us, she said: “No. Too small.” We adults know that size does not provide a litmus test of whether an animal has a brain, although size does affect some aspects of brain structure and, consequently, some aspects of thought. And research has shown that most of the different cell types in the brain, along with their chemical messengers, are the same across vertebrate species, including humans. Furthermore, the general organization of the different structures in the brain’s outermost layer, the cerebral cortex, is largely the same in monkeys, apes and humans. In other words, humans have a number of brain features in common with other species. Where we differ from them is in the relative size of particular regions of the cortex and how these regions connect, differences that give rise to thoughts having no analogue elsewhere in the animal kingdom.
Animals do exhibit sophisticated behaviors that appear to presage some of our capabilities. Take, for example, the ability to create or modify objects for a particular goal. Male bowerbirds construct magnificent architectural structures from twigs and decorate them with feathers, leaves, buttons and paint made from crushed berries to attract females. New Caledonian crows carve blades into fishing sticks for catching insects. Chimpanzees have been observed to use wooden spears to shish-kebab bush babies tucked away in tree crevasses.
In addition, experimental studies in a number of animals have revealed a native folk physics that enables them to generalize beyond their direct experiences to create novel solutions when exposed to foreign challenges in the laboratory. In one such experiment, when orangutans and chimps were presented with a mounted plastic cylinder containing a peanut at the bottom, they accessed the out-of-reach treat by sipping water from their drinking fountains and then spitting the liquid into the cylinder, thus making the peanut float to the top.
Animals also exhibit social behaviors in common with humans. Knowledgeable ants teach their naive pupils by guiding them to essential food resources. Meerkats provide their pups with tutorials on the art of dismembering a lethal but delectable scorpion. And a rash of studies have shown that animals as varied as domestic dogs, capuchin monkeys and chimpanzees maintaining dominance status, caring for infants, and finding new mates and coalition partners. Rather they can readily respond to novel social situations, as when a subordinate animal with a unique skill gains favors from more dominant individuals.
These observations inspire a sense of wonder at the beauty of nature’s R&D solutions. But once we get over this frisson, we must confront the gap between humans and other species, a space that is cavernous, as our aliens reported. To fully convey the extent of this gap and the difficulty of deciphering how it arose, let me describe our humaniqueness in more detail.
Source of Information : Scientific American September 2009
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