The Debunker: What Is a "Steep" Learning Curve?

by Ken Jennings

It's September and parents are rejoicing, because kids are (finally!) heading back to school! Crayons and binders and graphing calculators are flying off store shelves; beanbag chairs for dorm rooms are getting stuffed into the backs of station wagons. But maybe we all need to be taken to school, because a lot of the stuff we think we know about education would get us an 'F' on the final exam. Ken Jennings, that Jeopardy! guy, will be standing in front of the class all month with his red marker at the ready, to correct all that academic misinformation.

The Debunker: What Is a "Steep" Learning Curve?

Colloquially speaking, lots of things have a steep learning curve. The French horn. Arabic, Mandarin, and Hungarian. Adobe Photoshop. Those insanely complicated World War II board games that your weirdest college roommate liked to play. We understand the phrase "steep learning curve" to refer to difficulty, like the steepness of climbing a hill: it takes a lot of effort to make gains in proficiency when learning a daunting new skill set.

The Debunker

But there's a big problem with this usage: a "learning curve" is actually a real graph used in social sciences like psychology, education, and economics, and it works the opposite of how you're picturing. Like most graphs of this kind, time elapsed, as an independent variable, goes on the horizontal axis. The proficiency change in a learning curve goes on the vertical axis. This practice goes back as far as the 1880s, when German psychologist Hermann Ebbinghaus, studying the human memory, would have subjects memorize lists of nonsense syllables, and graph their performance against time.

So consider: if the actual learning on a learning curve is graphed vertically, then steepness is a good thing! It means that the learner is gaining proficiency over a relatively short period of time. In technical parlance, a skill with a "steep learning curve" is actually one where introductory skills can be learned very quickly, like playing the ukulele, or tic-tac-toe. But etymologists have found citations of people using the phrase wrong since at least 1973. Apparently this simple three-word phrase has a surprisingly, uh, challenging learning curve.

Quick Quiz: A minute to learn, a lifetime to master!" was the slogan of Mattel's "reversi" board game named after what Shakespeare character?

Ken Jennings is the author of eleven books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at or on Twitter as @KenJennings.