What Does It Mean to Say a Dog Is as Smart as a 2-Year-Old Child?

A dog trainer recently told me a dog has roughly the intellect of a 2- to 2½-year-old child. But what does that mean? Are we talking about understanding language? Emotional intelligence? Object permanence? Is this just one of those bogus factoids people repeat because they heard it somewhere? —Brian Griffin

Depends on your definition of “bogus,” Brian. The claim comes from Dr. Stanley Coren’s 1994 book The Intelligence of Dogs. As scientific assertions go, it certainly beats “we only use 10% of our brains” or “chewing gum stays in your stomach for seven years”—after all, it was in a real book by a guy with “Dr.” in front of his name! Of course, so was “men are from Mars, women are from Venus,” and that one’s not on track to eclipse Newton’s Laws of Motion anytime soon, so caveat emptor.

When it comes to language, experts believe an average dog knows 150 to 200 words. That puts it in the same ballpark as a 2-year-old. However, the 2-year-old will keep learning words—not to mention grammar—leaving the dog in the dust in a matter of weeks. (The dog has probably mastered not crapping all over itself, however, which goes a long way in my book.)

Emotional intelligence? I’m Team Cat, but even I have to admit that dogs slay at this. They can read emotional cues, they respond to voice tone and body language, and they even appear to console their human companions in times of stress. Is it all just a cynical long con to get bacon? Sure, but they’re good at it. I’d argue that dogs surpass not only human children, but human adults in emotional intelligence (not that either group sets the bar particularly high).

Object permanence—the ability to understand that objects continue to exist even when out of sight—is a major milestone in human cognitive development. (It’s what we’re teaching when we play peekaboo.) Surprisingly, dogs also get this, which puts them on par with 12- to 24-month-old children.

So, I dunno. Given that The Intelligence of Dogs was subtitled “A Guide to the Thoughts, Emotions, and Inner Lives of Our Canine Companions” and had heartwarming pictures of dogs on the cover, one suspects the comparison to toddlers was designed more to flatter the prejudices of dog lovers than to advance scientific inquiry. I’d have more sympathy if the book were called The Stupidity of Toddlers—but maybe that’s just my own prejudices showing.

Questions? Send them to dr.know@wweek.com.