There's a Scientific Reason You Can't Stop Thinking About Unfinished Tasks. Learning to Harness That Energy Will Make You More Productive. Why unfinished work captures our attention more than finished tasks, and how to leverage that psychological tendency for both personal and professional betterment.

Picture this: You're in the middle of a new project at work and everything is just flowing.

You're at the top of your productivity game — coming up with novel ideas and feeling a rush of excitement as you conjure up sentence after sentence with nary a pause. Then all of a sudden a colleague bursts that bubble.

His, "Hey, can we talk about tomorrow's presentation?" though cheerfully offered, has never come at a worse time. If this were a TV series, we'd call it a cliffhanger — that point of tension where a plot's left unresolved.

For some reason, for the rest of the day, as you sit through back-to-back meetings and strategize for the coming month, you can't stop thinking about that unfinished project. It just keeps popping up.

This is the Zeigarnik effect, a phenomenon wherein uncompleted tasks are remembered better than completed ones. Named after Russian psychologist Bluma (Wolfovna) Zeigarnik and first reported in 1927, it can certainly be distracting, but I've also found that it's possible to harness such mental energy to boost productivity.

How to use the Zeigarnik effect to your advantage

Although we can feel anxious in the process of and upon finishing a particular task, our brains are also ever in search of closure. If you begin to draw a circle, for example, your mind will automatically try to close the gap by picturing it completed. But you can make that effect work for you by leveraging such lingering thoughts — by learning to channel that desire into finishing projects and other deliverables.

Related: How to Start a 'Million Dollar' Morning Routine

A few tips on how to do that:

1. Write it down

At the end of each workday, I make a point of setting up tomorrow's tasks, either by starting a new page with a working title or leaving a few open tabs relevant to what I'll be taking on next. I find that by having started the process, it's more likely that I'll end up finishing it (my mind closing the circle).

This was one of the methods most helpful to me while completing the book, Automate Your Busywork: Do Less, Achieve More, and Save Your Brain for the Big Stuff (Wiley, 2023). At the end of each writing session, I'd start a fresh new page with at least one line of what I intended to work on next. And like magic, it would prompt me to jump in again, because there had been something left unresolved in my mind. Put simply, if you want to achieve something, all you need to do is begin it.

Related: See It Through: 5 Steps to Finishing What You Start

2. Focus on a single task

The Ziegarnik effect can also be an antidote to procrastination. By choosing to focus on only one task at hand, cognitive load is reduced, allowing the brain to better tackle "the big stuff." Because, while juggling multiple tasks at the same time can feel productive, too often it's just wheel-spinning — trudging through work without getting much done — a lot of it tedious, repetitive and inconsequential tasks that yet still seem necessary.

This is one of the key concepts in my book — how to retake our power by automating burdensome tasks — that to achieve success, it's necessary to keep focus on one thing, not juggle multiple projects.

Other experts agree: In his 2013 book The ONE Thing: The Surprisingly Simple Truth Behind Extraordinary Results (Bard Press), Gary Keller argues that "It is not that we have too little time to do all the things we need to do, it is that we feel the need to do too many things in the time we have. You can do two things at once, but you can't focus effectively on two things at once," adding in a later passage that it's vital to "…make sure every day [that] you do what matters most. When you know what matters most, everything makes sense."

Related: 5 Project-Planning Tips to Help You Meet Your Goals

3. Create your own cliffhangers

Our favorite TV shows know how to keep us wanting more. By ending a season with a "What happens next?!" writers are using the Ziegarnik effect to program our minds — to keep thinking about that unresolved plot over and over, even months down the line.

You can use this same approach to generate additional interest in your work. For example, deliberately regarding a project as incomplete helps you better iterate and innovate. If you're working on a presentation, say, you can take breaks during key points (where the topics become especially interesting) so you'll want to come back to them later on.

As an entrepreneur, I've found harnessing the Zeigarnik effect almost indispensable in the completion of larger projects. While it can lead to bouts of anxiety if left unchecked, when applied correctly, it can be a real boon to productivity and overall mental health, including bolstering self-esteem and confidence, as well as pride and a sense of accomplishment.