To-do lists: nearly everybody has one, but close to no one actually uses them as intended.

Don't believe me? If an honest appraisal of your own to-do list habits doesn't convince you (really, you never make them then lose them or forget about them?), perhaps some statistics from team productivity app iDoneThis might.

"At iDoneThis, we used to have a to-do task feature, and we discovered some interesting numbers demonstrating the common struggle to conquer our to-do lists," reports the company blog. The company found:

  • 41% of to­-do items were never completed.
  • 50% of completed to-­do items are done within a day.
  • 18% of completed to­-do items are done within an hour.
  • 10% of completed to­-do items are done within a minute.
  • 15% of dones started as to-do items.

To-do lists, it seems, are a fairly lousy reflection of what most folks actually get done, and most items that actually do end up getting done are completed very quickly after being added to the list, so quickly that you probably didn't need the list to remember the task anyway.

So if your to-do list isn't actually to help you organize and remember tasks, what is it that compels you to make one?

Perhaps it's the Zeigarnik effect. The what?:

The Zeigarnik effect states that people remember uncompleted or interrupted tasks better than completed ones.

Russian psychologist Bluma Zeigarnik first studied the phenomenon after noticing that waiters seemed to remember orders only so long as the order was in the process of being served.

The effect, in other words, is a handy psychological term for an experience you're probably already familiar with--that distracting and incessant way uncompleted tasks buzz around your mind. It’s annoying and, as iDoneThis explains citing the book Willpower as a source, a to-do list can act as a brain dump, quieting these intrusive thoughts of things yet undone: 

Studies by Baumeister and E.J. Masicampo found that the Zeigarnik effect was the unconscious "asking the conscious mind to make a plan," as opposed to asking the conscious mind to get off its butt to complete some tasks.

In one of these studies, a group of students was instructed to think about an important final exam while another group was told to make a specific study plan with details of what they would do, where, and when. (Nobody actually studied during the experiment.) When given word fragments to complete, the students who had been told merely to think about the upcoming test filled in exam-related words, while the study-plan group did not. Even though the planners had, in effect, spent more time thinking about their task, with no progress made on the task itself, as Baumeister and Tierney explain, "their minds had apparently been cleared by the act of writing down a plan."

Like the study plan made by the students, your to-do list is likely simply a way to clear your brain of the annoying intrusions caused by the Zeigarnik effect rather than an actual list you consult to remember what you need to do. This insight suggests some ways you can put your to-do list habit to better use. Don't scrap it; just understand that the key is to use it a way to map out your work rather than a mnemonic aid.

Use your to-do list to make a plan--specifically think through when and where you'll do the tasks and in what order--and you'll find you maximize the actual benefit you get out of the exercise, a quieter mind rather than a series of boxes you'll actually tick.

Are you guilty of creating to-do lists and then completely ignoring them?