It’s easy to think of history as a march of progress, with humans growing smarter and more capable over time. But if you think about how evolution really works, Stanford biologist Gerald Crabtree argues in a new article in the journal Trends in Genetics, the march may be the opposite direction: We’re likely getting dumber.
Crabtree reasons that our intelligence and emotional stability would have developed “in a world where every individual was exposed to nature’s raw selective mechanisms on a daily basis.” Before agriculture and urban society, human beings would have lived or died on their spatial reasoning skills: Learning to build shelters and tools took serious intelligence. By comparison, many contemporary activities that we think of as more intellectually taxing, like doing math problems, are actually computationally simple. That’s why your phone can beat you at chess, but even the most advanced robots are bad at washing dishes.