Health & Science | The Week

As a species, we’re not as smart as we used to be. That’s the theory of a Stanford University researcher who believes that human intelligence started to decline when civilization made life

easier and allowed dimmer individuals to survive and pass on their genes. “I would wager that if an average citizen from Athens of 1000 B.C. were to appear suddenly among us, he or she would

be among the brightest and most intellectually alive of our colleagues and companions,” Stanford geneticist Gerald Crabtree tells The Independent (U.K.). He figures human beings reached

their intellectual peak 2,000 to 6,000 years ago, when life was so harsh and individualistic that bad judgment generally led to death. Farming progressively led to denser communities where

people could collectively ensure one another’s welfare. As a result, evolutionary pressure—the hunt for prey, the avoidance of predators—no longer culls the slow-witted the way it once did.

“A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died,” Crabtree says, “whereas a modern Wall Street executive that made a similar

conceptual mistake would receive a substantial bonus and be a more attractive mate. Clearly, extreme selection is a thing of the past.”

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