Why It's Good That Your Brain Is Shrinking

Our brains are 10 percent smaller than our ancestors' brains. But it's not a bad thing.

Over the past 30,000 years, the average human brain has shrunk by 10 percent, or about the size of a tennis ball. Though that may sound worrisome, in fact, scientists see the shrinkage as a good thing.

According to David Geary, a psychology professor at the University of Missouri, brain size decreased as the world's population density increased. "As complex societies emerged, the brain became smaller because people did not have to be as smart to stay alive," he said.

This doesn't mean humans are getting dumber, of course. Instead, scientists hypothesize a shrinking brain means the species is becoming leaner and more efficient.

But the downsizing does not mean modern humans are dumber than their ancestors -- rather, they simply developed different, more sophisticated forms of intelligence, said Brian Hare, an assistant professor of anthropology at Duke University.

He noted that the same phenomenon can be observed in domestic animals compared to their wild counterparts.

So while huskies may have smaller brains than wolves, they are smarter and more sophisticated because they can understand human communicative gestures, behaving similarly to human children.

Turns out being a pea-brain might not be so bad after all.

photo (cc) via Flickr user andypowe11