Working at the secretive Google X lab, researchers from Google and Stanford connected 1,000 computers, turned them loose on 10 million YouTube stills for three days, and watched as they learned to identify cat faces.

The research, thus summarized, is good for a laugh. “Perhaps this is not precisely what Turing had in mind,” wrote The Atlantic’s Alexis Madrigal. Sure it was, countered The Cato Institute’s Julian Sanchez: Google was training its computers to pass the “Purring Test.”

But what’s most fascinating about the study is that the researchers didn’t actually tell the computers to look for cat faces. The machines started doing that on their own.