Got a crotchety old guy who kept telling you that youngsters today are getting dumber by the minute (right before he told you to get off his lawn)?
Well, he may be onto something: scientists discovered that our brains are actually shrinking!
The downsizing of human brains is an evolutionary fact that took science writer Kathleen McAuliffe by surprise.
"I said, 'What? I thought it was getting bigger!'" she tells NPR's Jacki Lyden. That was the story up to 20,000 years ago, she learned. Then, the brains of our ancestors reversed course and started getting smaller — and they've been shrinking ever since.
Cro-Magnon man, who lived in Europe 20,000 to 30,000 years ago, had the biggest brains of any human species. In comparison, today's human brain is about 10 percent smaller. It's a chunk of brain matter "roughly equivalent to a tennis ball in size," McAuliffe says.
The experts aren't sure about the implications of this evolutionary trend. Some think it might be a dumbing-down process. One cognitive scientist, David Geary, argues that as human society grows increasingly complex, individuals don't need to be as intelligent in order to survive and reproduce.
I don't know about the science, but it sure explains Jersey Shore! http://www.npr.org/2011/01/02/132591244/our-brains-are-shrinking-are-we-getting-dumber