The Source of Human Intelligence

What made humans intelligent? What is the source of our remarkable reasoning powers? Why don’t other animals share them?

Just because I’m a spiritually-minded guy doesn’t mean I don’t believe in evolution. There’s too much evidence to ignore it. But if evolution is right, then there must be answers to the questions above.

Evolution can generate spectacular results when direct competition is the driving force. Consider the amazing speeds of the gazelle and the cheetah. As proto-gazelles got faster, proto-cheetahs had to get faster, too. As proto-cheetahs got faster, proto-gazelles had to get faster yet. For both species, speed meant life and sloth meant death. Could the human brain be the result of some kind of life-or-death social competition?

The theory is called the Machiavellian Intelligence Hypothesis, and it basically says that human intelligence evolved to outwit other humans in social situations. The social structure of all higher primates is quite complex, and it could be that proto-humans began engaging in a sort of race, in which those who had the intelligence necessary to compete more successfully in the social games had more children.

This post at Language Log gives an example of the kinds of amazingly complex social interactions that even our children can find themselves in. If it seems impossible to untangle, try substituting the names of people you know instead of the anonymous letters. This will trick your brain into turning on your social analysis circuits (i.e. the second, third, and fourth circuits), and everything will become clear.
If you think about your own social circle, you’ll find that it’s similarly complex, once you look at it. Luckily, our brains seem to be wired to handle this sort of thing quite well.

An interesting side point is this: if this theory is correct, then, over millions of years, human intelligence will only continue to increase. As people get smarter, their social interactions will get more complex, and the smarter they’ll have to be to get ahead in them.

I don’t know how any of this squares with the idea that we are spirits inhabiting physical bodies. The brain clearly seems to have been formed by the physical forces of evolution, and physical injuries to the brain definitely affect personality and memory and so forth. That all points to the conclusion that your personality and “soul” are generated by the brain itself. And yet… there’s plenty of evidence that some part of us — some part with memory and personality — persists after the brain is completely gone.

Once I heard a possible solution to that question: the brain doesn’t generate personality, memory, and spirit; it’s more like a receiver. It’s like a radio. If you break a radio, it doesn’t play music any more; but that doesn’t mean the radio has little musicians inside it.

Anyone have any ideas?