Intelligence evolved through courtship pressures
Miller points out that musty theories claiming we developed our impressive cerebra from, for example, tool use, don’t seem to fit the facts. The stone axes chipped by our one-pound-brained ancestors were about as good as those made by their three-pound-brained successors. Instead, Miller suggests that the ramping up of IQ was the result of 100,000 generations of pre-human courtship operating on fitness signals made possible by brain power.
“The brain’s a really good indicator of fitness because its growth depends on at least half of the genes that humans have,” he says. “A brain, after all, is very complex, very sensitive to genetic mutations, and costs a lot of energy to run.”
If you have a good brain, you have good genes. They’re our flashy tail.
But it’s a messy business to literally display your brain. So how can a quality cranium signal its superiority to a mate? It does so with behaviors such as speaking well, or by demonstrating musical ability, a sense of humor, or creativity. These activities depend upon many parts of the brain, and consequently are reliable indicators of mental merit.
By Randall Parker at 2002 September 30 03:22 PM