Talk about optimism: A genetics professor in California argues that human beings have been dumbing down for thousands of years and will only grow dimmer down the road, the Independent reports. We probably peaked as hunter-gatherers, who survived by their wits, and saw a decline in natural selection of the intellect as we shifted to agricultural and city life, argues Gerald Crabtree of Stanford University. Then we just got dumber as genes mutated with each generation. (His paper is in two parts, here and here.)
"I would wager that if an average citizen from Athens of 1000BC were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions," writes Crabtree. "Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues." But not all are convinced: "At first sight this is a classic case of Arts Faculty science," says a geneticist in London. "Never mind the hypothesis, give me the data, and there aren’t any."