A while back I blogged about the One Hour Rule of Memory: if we don’t give our minds an hour to digest what we learn, we’ll usually forget. When we learn, the mind grows branches between brain cells. If we don’t allow enough time for branches to grow, learning is lost.
This has enormous implications for the way we learn. It suggests that much of our early education could actually be what we thought of it as kids – a waste of time.
But it gets worse. Or better, depending on how we look at it. Another big learning factor is what I call The Twenty Minute Rule of Hard Thinking. “After only 20 minutes of hard thinking,” writes psychologist and learning expert Susan Weinschenk, “you’ve used up all the glucose in the brain that’s needed for effortful thinking.”1 The brain runs out of gas, so to speak, after twenty minutes.
I feel this when reading non-fiction books. Within twenty minutes, I’m fried. I need a nap. Or at least a break. I feel the same when tackling a tough work project. After twenty minutes of focused attention, it’s time for a short break. I’m out of juice.
So whether we’re doing heavy learning or teaching heady stuff, we’ve got to take breaks every twenty minutes.
I can tell you from personal experience teaching and learning, this rule liberates. Now I read in shorter chunks, spaced out over the day. And I’ve been lecturing with this rule in mind for several years now. During a three hour college lecture session or a half-day seminar, I try to go for 18 minutes then take a 2-minute break. Three breaks an hour. Students tell me it’s transforming. Learners feel refreshed, and I get credit for being a better teacher than I really am.
Somebody please, tell this to the seminar guys, the teachers, the politicians, the ministers. We’d all be better off if everyone with something important to say understood the Twenty Minute Rule.
1Susan M. Weinschenk, Ph.D., How to Get People to Do Stuff (San Francisco: New Riders, 2013), p. 142.
