A new scientific study lends credence to the idea that to-do lists don’t work. The study suggests that, when it comes to taking action and creating results, humans have two-track minds.
The study, “Divided Representation of Concurrent Goals in the Human Frontal Lobes,” summarized in the Ars Technica story “In multitasking, more than two tasks do not compute,” used brain scans to observe brain activity while people did two or more things at once, and when they switched tasks or were interrupted. The resulting picture is of a brain that has two areas for guiding tasks. They can work together, for focus on a single task, but more often they split up, with one focusing on one task, the other one focusing on a second task.
The interesting thing is what happens when you introduce a third simultaneous task or an interruption. Then both of the two areas of the brain start switching among all the tasks. This can create the subjective experience of pursuing three tasks at once, but the “pursuit” part is largely an illusion. People make lots of mental errors in this situation, leading to mistakes, but more importantly, they start taking meaningless actions that don’t move them toward the objective of each task.
In other words, when we think we’re working on three tasks at once, we’re really not. We’re just going around in circles, taking largely ineffective actions. We don’t realize how ineffective our actions are because our brains aren’t able to effectively supervise our actions and progress in more than two tasks at one time.
To illustrate this, imagine the task of doing an accounting exercise on a sheet of paper. An effective action could be adding up a column of numbers and writing the result. Ineffective actions, the quality of action we tend to do when we are trying to do three or more things at once, could include shifting the paper around, putting the pen down and picking it up again, or drawing lines and boxes on the sheet of paper. Actions such as these make us believe we are continuing to work on the accounting task, but in fact, they don’t move us any closer to answering the accounting question we are working on.
To my mind, this means that it doesn’t matter so much whether you’re working on one task at a time or two. Taking on a second task might make you slightly more productive, or less, but not enough to care about. But add a third task, and your pace of work will tend to fall by 30 percent or more, perhaps as much as 80 percent — a productivity disaster if you’re trying to get a list of things done today. Add a fourth and fifth task, and it will tend to make things worse, but not much worse — at three tasks, your brain is already scrambling.
Now, let me relate this finding to the way people typically approach a to-do list, or any time management system. The to-do list gives you a list of tasks to do. The to-do list itself is a task. If you’re working quietly at your desk with no interruptions, doing only one task from the to-do list at a time, this ought to work fine. You can keep track of the to-do list in one area of the brain, while you focus on the specific task you’re doing with a second area of the brain. You work productively on one task after another, without losing track of the list.
So far, so good. Throw in any interruption at all, though, and the train goes off the tracks. You might flounder unproductively through the three tasks, until another interruption gives you four tasks, and so on. You might set aside the task you were working on, but that means essentially having to start it all over again later, with the work you did before the interruption largely wasted. Or you might set aside the to-do list — and if you get to the end of the day and realize that you forgot your to-do list way back around 10 a.m., this helps to explain how that can happen.
The “right” approach, according to time management systems, is to set aside both the to-do list and the task and handle the interruption — then return to the to-do list after the interruption is over. But this too is unproductive. Every time you have an interruption, the work you were doing for the previous ten or twenty minutes, or since you began that task, is lost. As a last-ditch effort to save the time-management paradigm, many people lock themselves in their offices for four hours a day with telephone and e-mail turned off and a “Do Not Disturb” sign on the door — but this too creates problems more serious than the ones it solves.
To-do lists don’t work. Time management systems aren’t an improvement because they still tell you what to do at a particular time or in a particular sequence. All efforts at time management share the same problem — the human brain cannot effectively track what to do, the current priority, and the latest interruption all at once.
The solution, in my opinion, is not to throw away the to-do list, but to make it much shorter. Working from a to-do list may be unproductive, but we still have to keep up with the demands of the situation. But it is important to keep the to-do list as short as possible so that the whole day doesn’t get bogged down in the unproductive churn of the to-do list. The ideal to-do list is one you can complete before lunch, so that you can spend your afternoon doing your real work.
Having a shorter to-do list means doing more things immediately; staying well ahead of deadlines; rejecting marginal tasks from the outset; doing some tasks at a lower level of control so that they can be finished quickly; trusting others to do some tasks; leaving well enough alone. For managers, it means a strict rule against assigning any task at all to a worker who is already overloaded. Managers can do a lot to avoid the effects of worker overload by rejecting more tasks, tasks that ultimately won’t get done anyway, at the outset.
Most of all, though, it means having a smaller backlog of work to be done. It’s the backlog of work that forces you to add the task of managing your work from minute to minute, and it is that task that allows interruptions to throw you off. The book Fear of Nothing lays out the process for getting out of the backlog and into the more powerful, more productive position of working directly from goals and inspirations most of the time. The irony of this is that if you give yourself less to do, you will get more done.
This is something we’ve seen for years — the most successful and productive people are rarely the people who have the longest to-do lists. And now there is a scientific explanation for why that might be so.