The Zeigarnik effect describes the way unfinished tasks remain active in our mind, intruding into our thoughts and our sleep until they are dealt with, much like a hungry person will notice every restaurant and appetizing smell on their way home and then lose all interest when they’ve had their dinner. You may have noticed the effect yourself during your exams in school, when you crammed before the exam, sat it, and then promptly forgot everything you had just learned because you no longer had any use for the information.
How it all started
The effect is named for Bluma Zeigarnik, a Lithuanian-Soviet psychologist and psychiatrist. As the story goes, she was out for dinner one night at a restaurant in Berlin with a large group of colleagues when she noticed her waiter’s impressive ability to remember all the complex food and drink orders. After everyone had finished eating and had left the restaurant, Zeigarnik realized that she had forgotten her purse, so she walked back, found the waiter who had served them, and asked for his help. But he did not remember her; where had she been sitting?
When she asked him how he could have forgotten her so quickly, the waiter apologized and told her that he always forgot his orders (and customers) as soon as the meals had been delivered and paid for. The only way that he could do his job was to focus exclusively on the open orders he still had to deal with. This suggested that incomplete tasks remain in the mind until they are completed. Zeigarnik decided to investigate.
In a series of experiments she asked different groups of children and adults to complete around 18 simple tasks, such as stringing beads, solving puzzles, doing math problems, and folding paper. She allowed half of the participants to complete their tasks and interrupted the other half partway through, asking them to move onto something else. An hour later, she asked the participants to describe what they had been working on. She found that those who had had their work interrupted were about twice as likely to remember what they had been doing as the participants who had actually completed the tasks.
Her string of experiments also revealed some modifying factors: tasks that were interrupted in the middle or toward the end were more likely to be recalled than those that were interrupted near the beginning, tasks that were experienced as difficult or beyond a person’s capacity were generally forgotten, and people who were tired were more likely to recall finished tasks. There were also significant differences between people’s performances, with those who were more “ambitious” — that is, competitive — or more interested in the task at hand being better able to recall unfinished tasks and quicker to forget tasks when they were finished.
The Zeigarnik effect was subsequently studied by many other researchers who had varying degrees of success in replicating Zeigarnik’s findings. Forty years later, a review of their research by American psychologist Earl Butterfield concluded that there seemed to be no universal pattern to the ability to recall unfinished tasks, but that the differences observed in the results was probably due to motivation.
How it works
Zeigarnik was supervised by legendary Gestalt psychotherapist Kurt Lewin and, therefore, strongly influenced by Gestalt theory. Her hypothesis was that people are more likely to remember incomplete tasks because these unfinished undertakings spur “psychic tension” within them. The state of tension and the memorial advantage of the unfinished tasks remain while the person’s mental “need for completion” remains unfulfilled. But once the task is complete, the psychic tension is relieved, and the task can be purged from memory.
The current thinking is that the Zeigarnik effect is caused by the way our memories work.
When information is perceived, it is stored in sensory memory for a very brief time — anywhere from mere milliseconds to five seconds. When we pay attention to it, it is transferred to short-term (working) memory, which is limited in both capacity and duration; we can only retain a certain number of things, and we have to keep rehearsing this information in order to hold onto it. So, if you are a waiter dealing with a lot of hungry customers, in order to do your job properly, you have to keep pulling your customers’ orders back into your awareness until they have finished their meals, the bills are paid, and they have left. Then you can forget all about them.
How to make it work for you
Once you understand how the Zeigarnik effect works, you can use it to improve your productivity in several ways.
- Start somewhere… anywhere.
You know that you’ve got a deadline in a week and you’re inclined to leave the whole thing till the 11th hour. Don’t. Just start somewhere. Block out 20 to 30 minutes of your time, and get stuck in. You don’t have to start with the hardest bit; try something easy first. Once you’ve made a start on your task, however trivial, it will niggle away in the back of your mind and nudge you to do a bit more… and a bit more… until it’s done.
You can also get the ball rolling by creating a brief outline of what you need to do. Recent research has shown that the motivation to complete an unfinished task is higher the clearer we are about what needs to be done to complete it. The authors called this the Hemingway effect, after the author Ernest Hemingway who, when asked during an interview, “How much should you write in a day?” replied, “The best way is always to stop when you are going good and when you know what will happen next. If you do that every day when you are writing a novel, you will never be stuck.”
- Schedule tactical breaks to improve information recall
The Zeigarnik effect implies that taking breaks while working on something will increase our ability to retain information. Research also shows that people who take breaks from their work — anywhere from five minutes to an hour — to do something completely different tend to retain their focus better than those who try to cram their learning all into one session.
So, if you’re trying to study, spread the learning over multiple sessions. Rather than trying to get through it all in one go and going through the same information over and over again, stop and pull yourself away. According to Zeigarnik’s research, this should be when you are “most engrossed.” While you’re grabbing a coffee or enjoying a walk, you’ll notice that your mind keeps returning to the information you were trying to understand. The break will give you time to reflect on what you’ve learned and to consolidate your thoughts before you resume your study session, feeling fresh and focused.
- Set realistic goals
The Zeigarnik effect can also help us to understand and work within our limitations. If you have a tendency to keep too many balls in the air and you start to feel swamped, knowing that intrusive thoughts tend to accompany uncompleted tasks should help you to appreciate that each new task is essentially an interruption of whatever you were doing before. This should motivate you to set reasonable limits on the amount of multitasking you attempt, thereby increasing your work performance while reducing your frustration.
Knowing that this bias affects us all means that you can remind your inner critic that anyone can feel overwhelmed in the face of too many incomplete tasks, and that it’s not a reflection of your abilities. And each time you successfully complete a task, you can bask in the sense of accomplishment and satisfaction that accompanies your achievement and use the positive momentum to get started on the next one.
- End the day with a to-do list
Thomas Edison famously said, “Never go to sleep without a request to your subconscious.” But research also shows that worrying too much about unfinished tasks tends to result in sleepless nights. Happily, research has also come up with a way to help you switch off: make a clear plan of what you still have left to do.
A 2011 study by E. J. Masicampo and Roy Baumeister from Florida State University showed that the mere act of planning how to do something frees us from the cognitive burden of unfinished tasks. In one of their experiments, students who were asked to think about an upcoming exam were unable to focus on a subsequent word completion task. Their minds kept wandering back to their looming exam. The effect was eliminated among participants who had been allowed to make a plan for when and how to study for the exam. In other words, not only did making a plan get someone further toward their goal, it also freed their cognitive resources for other pursuits.
Notably, neither group had actually done any studying for the exam. The Zeigarnik effect may be less an alarm that keeps chirping until a task is completed and more a prompt from our subconscious to urge us to make a plan. As soon as this plan is formed, the subconscious mind can stop harassing the conscious mind and allow it to relax until it’s time to resume the task as scheduled.
It’s important to make the plan specific. In another experiment, simply reflecting on the way they could fulfill their objectives did not stop participants from having intrusive thoughts about their goals. It was the participants who committed to a specific future course of action who enjoyed some peace of mind. Put differently, thinking “I should exercise” disturbs the unconscious mind because it calls attention to unmet goals and leaves the unconscious mind uncertain about how to proceed. But once the conscious mind articulates “I will go jogging tomorrow morning before work,” the unconscious knows precisely how to proceed and no longer needs to bother the conscious mind with intrusive thoughts about exercise.
When it comes to turning off thoughts of unfinished work, one way of achieving peace of mind would be to devote some time at the end of each day to review the day’s accomplishments and then to write down what more needs to be done, and how. But another way may be to delegate — thinking about how other people can help to reach a goal has been shown to reduce a person’s motivation to expend effort on that goal. As long as the urgency of the goal is lessened and the need to act is delayed, the intrusive thoughts may go away. Your subconscious mind loves it when a plan comes together. However it comes together.
- Zeigarnik, B. (1927). Das Behalten erledigter und unerledigter Handlungen [On finished and unfinished tasks]. Psychologische Forschung, 9, 1-85.
- Butterfield, E. C. (1964). The interruption of tasks: Methodological, factual, and theoretical issues. Psychological Bulletin, 62(5), 309-322.
- Cascella M, Al Khalili Y. Short Term Memory Impairment. [Updated 2022 Feb 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: ncbi.nlm.nih.gov/books/NBK545136/
- Oyama, Y., Manalo, E., & Nakatani, Y. (2018). The Hemingway effect: How failing to finish a task can have a positive effect on motivation. Thinking Skills and Creativity, 30, 7-18.
- Ariga, A., & Lleras, A. (2011). Brief and rare mental “breaks” keep you focused: Deactivation and reactivation of task goals preempt vigilance decrements. Cognition, 118(3), 439-443.
- Syrek, C. J., Weigelt, O., Peifer, C., & Antoni, C. H. (2017). Zeigarnik’s sleepless nights: How unfinished tasks at the end of the week impair employee sleep on the weekend through rumination. Journal of Occupational Health Psychology, 22(2), 225-238.
- Masicampo, E. J., & Baumeister, R. F. (2011). Consider it done! Plan making can eliminate the cognitive effects of unfulfilled goals. Journal of Personality and Social Psychology, 101(4), 667-683.
- Fitzsimons, G. M., & Finkel, E. J. (2011). Outsourcing self-regulation. Psychological Science, 22(3), 369-375.