Today, I was going through David Mamet’s Masterclass, and he came to a part I found fascinating during his discussion of his play American Buffalo.
He talked about how human beings have an “alertness” cycle built into them when they’re doing tasks that causes them to mentally take a moment to casually check their environment every seven minutes. Also, every twenty minutes into doing something, there’s a bigger mental break as humans fully stop what they’re doing to access their situation. These are holdovers from the times of our ancestors, when paying attention to our environment could mean life or death, and are hardwired into human beings.
As a teacher, I already knew about the twenty minute rule – humans seem to have a limit of about twenty minutes to pay attention to a topic or subject before they get restless unless they’re really stimulated or engaged. After twenty minutes (some say 18), getting a class to stay on topic can be like rolling a boulder uphill, and so I follow the best practice of trying not to stay on one topic more than twenty minutes when lecturing. Instead, I will try to turn the lecture into a series of smaller parts, and when possible have activities or videos to add a little variety to things.
But, what I didn’t know was that there’s a standard smaller “unit” of seven minutes before people’s attention does a lighter reset. Mamet himself, who spends a lot of time in theaters, gives the anecdote that if the play starts at 8:00 the audience will quiet down precisely at 8:06 as their attention shifts fully to the most interesting thing happening – the play. He claims you can set your watch by it. I haven’t been able to find many other references to it beyond many business sites claiming it’s true, although the website Medium found something similar. They did a study of their large readership’s reading habits for their blogs, and discovered that seven minutes of attention was where readers’ interest in content seemed to peak. After that it dropped off, and if articles took longer than seven minutes to read the readership was less inclined to keep reading.
Thus, as a writer always thinking about optimization, these numbers 7 and 20, made me wonder if there might be a hack here for writers as well. Is there way for writers to be calibrating our content to fit into these attention blocks as a way to achieve maximum readability and keep our audiences hooked?
It looks like there is!
The answer to keeping the readers reading is putting in a natural break paired with a dramatic question like a cliffhanger, or a bit of suspense, at the seven minute mark. That way they can either stop for the moment at a good point to rest, or they can plunge on to another seven minute binge to find out what happens next.
But, how long is seven minutes of reading content?
Well, that depends on the reader and the difficulty/complexity of the content itself. However, according to Forbes.com your average American Adult reader reads roughly 300 words per minute. So, doing some simple math, seven minutes of reading means 2100 words.
So, to answer the question that endless numbers of new writers ask every day – “How long should my chapters be?” The answer is 2100 words, or if you want to simplify it a bit, make it 2000 words (since it doesn’t hurt to wait for the slower readers).
Of course, shorter would be fine too, but with shorter chapters (or scenes, since this could also be done with scene length) you’d naturally run into the problem that the seven minute gap would come at a random place in your story instead of a controlled moment when you can give them something that grabs their attention to keep them going.
What about the twenty minute limit?
Well, similarly, 20 minutes of reading is roughly 6000 words. So, if you prefer long chapters, you might think about 6000 being your upper limit before you take a break or insert a dramatic pause. And, even if you’re doing 2000 word chapters, putting a more major dramatic moment every three chapters might be something worth doing to be ready when the reader hits their major restless moment.
Naturally, in the end, you can make your chapters whatever length you like, but there’s no harm in being a little scientific and using a little human psychology to make your writing even more addictive.