Psychology of the to-do list: People who scribble a to-do list to "get it out of my head" aren't just organized; a 2011 study found that making a plan shuts down the nagging of unfinished tasks

You know that itch when you remember, halfway through a Netflix episode, that you never emailed your landlord back. According to a 2011 study, ‘Consider it done! Plan making can eliminate the cognitive effects of unfulfilled goals,’ published in the Journal of Personality and Social Psychology by psychologists E.J. Masicampo and Roy Baumeister at Florida State University, there's a surprisingly simple remedy for that itch. You don’t have to finish the task. You just need to plan it.

Your brain keeps a tab open, whether you like it or not
Psychologists have described this kind of mental lingering for almost a century. The Zeigarnik effect, first described by psychologist Bluma Zeigarnik in 1927, is the tendency for unfinished tasks to occupy more attention and memory than finished ones. Masicampo and Baumeister wanted to find out what stops this.

Their study shows that this is not just a vague feeling. In their experiments, people given an incomplete goal, something as mundane as a task they still had to do, showed measurable signs of mental background noise. They experienced more intrusive thoughts while reading an unrelated passage, they were faster to recognize goal-relevant words than other words, and they performed more poorly on an anagram task not related to the original task.


The researchers then checked whether the effect showed up beyond sleep and found the same kind of goal-related activation in memory and attention: unfinished goals made participants faster to recognize words tied to the task, but not other words. They also reported worse performance on a separate anagram test, which they interpreted as evidence that incomplete goals can consume cognitive resources even when people are trying to do something unrelated.

Basically, your brain keeps a tab open in the background, running silently, consuming processing power you didn’t know you were wasting.

Writing the plan, not finishing the task, is what turns it off
And here is the part that even surprised the researchers. The study found that when participants were asked to write down a specific plan about how, when, and where they would complete the task, the intrusive thoughts stopped. The faster recognition of goal-related words dropped. Anagram performance was back to normal. None of this was actually required to do the task. Just deciding on a concrete plan was enough to quiet the mental noise.

According to the authors, the key was not just any jotting down, but writing a concrete implementation plan specifying how, when, and where the task would be done. They found that this eliminated the lingering goal effect even when participants never actually completed the task right away, implying that the brain responds to a credible plan as if the task has been temporarily filed away.

Interestingly, the researchers also found that this effect wasn’t really about feeling better emotionally. The findings indicated that alterations in mood did not explain the reduction in intrusive thoughts. The relief appears to be a cognitive phenomenon rather than an emotional one, more akin to closing a browser tab than soothing a feeling. The researchers themselves summed it up in their conclusion: once a plan is made, the drive to attain a goal is essentially put on hold, freeing up mental space until the moment you actually mean to act on it.

Your nightly to-do list might be doing double duty
If this sounds familiar, there is a reason. In a 2018 study, ‘The effects of bedtime writing on difficulty falling asleep: A polysomnographic study comparing to-do lists and completed activity lists,’ researchers at Baylor University found that college students who spent five minutes writing a to-do list before going to bed fell asleep faster than students who wrote about tasks they’d already done. It wasn't just a self-reported hunch.

The Baylor team kept the protocol simple and strict: students stayed in the lab on a weekday night, were randomly assigned to write either upcoming duties or recently completed activities for five minutes, and then were allowed to have lights out at 10:30 pm. Lead author Michael K. Scullin said the study used polysomnography, the “gold standard” in sleep measurement, and that the sample of 57 was appropriate for a lab experiment, though larger studies would be useful.

As lead researcher Michael Scullin explained in Baylor's official release, writing down what is still pending offloads those thoughts from working memory, a finding consistent with what Masicampo and Baumeister found about planning quieting the mind.

A quick, honest caveat
Let’s be upfront about something. The original Zeigarnik effect, the claim that incomplete tasks are simply better remembered than completed ones, has not had such an easy time in recent attempts at replication. A 2025 meta-analysis, ‘Interruption, recall and resumption: a meta-analysis of the Zeigarnik and Ovsiankina effects,’ published in 2025 in the journal Humanities and Social Sciences Communications, which reviewed decades of research, found no reliable memory advantage for unfinished tasks, but a reliable tendency for people to want to return to and finish what they had started. That doesn’t undo the Masicampo and Baumeister findings that were about intrusive thoughts and mental interference rather than pure memory recall, but it is a fair reminder that not every piece of a nearly hundred-year-old idea has aged the same way under modern scrutiny.

The takeaway for your Sunday scaries
None of this means you can plan your way out of real work. The dishes still need doing. The email still needs sending. But if your Sunday night brain can't stop playing your unfinished to-do list on repeat, the fix might not be more willpower. It could just be five minutes with a notebook, writing down exactly when and how you will deal with it. Your brain, it turns out, mostly just wants to know there is a plan.