Now imagine if my colleague behaved like a search engine — if, upon being queried, he delivered a five-minute lecture on Waziristan. Odds are I'd have brusquely cut him off. "Dude. Seriously! I have to get back to work." When humans spew information at us unbidden, it's boorish. When machines do it, it's enticing. And there are a lot of opportunities for these encounters. Though you might assume search engines are mostly used to answer questions, some research has found that up to 40 percent of all queries are acts of remembering. We're trying to refresh the details of something we've previously encountered.
If there's a big danger in using machines for transactive memory, it's not about making us stupider or less memorious. It's in the inscrutability of their mechanics. Transactive memory works best when you have a sense of how your partners' minds work — where they're strong, where they're weak, where their biases lie. I can judge that for people close to me. But it's harder with digital tools, particularly search engines. They're for-profit firms that guard their algorithms like crown jewels. And this makes them different from previous forms of transactive machine memory. A public library — or your notebook or sheaf of papers — keeps no intentional secrets about its mechanisms. A search engine keeps many. We need to develop literacy in these tools the way we teach kids how to spell and write; we need to be skeptical about search firms' claims of being "impartial" referees of information.
What's more, transactive memory isn't some sort of cognitive Get Out of Jail Free card. High school students, I'm sorry to tell you: You still need to memorize tons of knowledge. That's for reasons that are civic and cultural and practical; a society requires shared bodies of knowledge. And on an individual level, it's still important to slowly study and deeply retain things, not least because creative thought — those breakthrough ahas — come from deep and often unconscious rumination, your brain mulling over the stuff it has onboard.
But you can stop worrying about your iPhone moving your memory outside your head. It moved out a long time ago — yet it's still all around you.
Clive Thompson is a longtime contributing writer for the New York Times Magazine and a columnist for Wired.