Zeigarnik Effect

Origins of the Zeigarnik Effect

The Zeigarnik effect is the tendency for tasks that have been interrupted and left unfinished to be remembered better than tasks that have been completed.

Zeigarnik (1927) traced the idea to waiters. They seemed to remember an order only while it was still being served, then promptly forgot it once it was paid (Denmark, 2010).

This waiter anecdote is usually told as Zeigarnik’s own observation, though it is often attributed to her supervisor instead. The story may be apocryphal.

Later historical scholarship treats it as a framing device rather than a documented event (MacLeod, 2020). It illustrates the idea; it is not evidence for it. The evidence came from the experiments that followed.

At the time, Zeigarnik was supervised by the Gestalt theorist Kurt Lewin. She was immersed in the writings of Gestalt psychologists such as Wolfgang Köhler, Kurt Koffka, and Max Wertheimer (MacLeod, 2020).

Gestalt psychology, founded in the early 20th century, holds that whole human behaviour cannot be reduced to an analysis of its separate parts.

The Tension-System Mechanism

Zeigarnik built her research inside Lewin’s field theory, which modelled a person as a system of psychological forces.

Taking on a task, in this model, creates an intention, and an intention sets up a tension system: a state of readiness directed at a goal (Lewin, 1935). The tension seeks release. Lewin’s group called such intentions quasi-needs, need-like states that push toward their own discharge.

While a tension system stays active, it keeps the goal, and the memory of the task, in an easily accessible state. Completing the task discharges the tension, the system relaxes, and the task fades into ordinary forgetting.

The tension is gone.

An interruption leaves the system charged, so the task persists in memory. Zeigarnik’s project was to find a behavioural sign of this otherwise invisible process, and memory offered exactly that.

Zeigarnik’s Initial Experiments

Aim: Zeigarnik (1927) tested whether interrupted, uncompleted tasks are remembered better than completed ones. The idea was simple. Any such difference would count as evidence for Lewin’s tension systems.

Method: Participants worked individually. Each completed a series of between 15 and 22 short tasks, taking a few minutes each. Some were tactile, such as stringing beads; others were mental, such as solving a puzzle.

In her main experiment, Zeigarnik gave 32 adults 22 tasks, including thread winding, multiplication, and drawing. The tasks varied widely.

The experimenter let participants complete about half of the tasks. The other half were interrupted “when the person was most engrossed” in the activity. The materials were then removed from view.

After an hour’s delay, participants were unexpectedly asked to recall everything they had worked on.

Zeigarnik then replicated the design twice more: with 15 more adults individually, and in groups of 47 adults and 45 adolescents.

Results: Participants recalled interrupted tasks far more often than completed ones. Roughly twice as many, in fact (Zeigarnik, 1927; Denmark, 2010). Recall was strongest near the middle or end of a task, when engagement was highest.

Two smaller follow-up experiments, with 12 adults, tested whether belief in resumption mattered. It made no difference.

Zeigarnik told six participants that six tasks would be resumed and six would not. She never resumed any of them. Interrupted tasks were still recalled better regardless (MacLeod, 2020).

Moderators: Zeigarnik did not treat this as a universal law. Recall was strongest in participants with high ambition. It was also strongest in those who saw an incomplete task as a personal failure.

It weakened when a participant found the interruption a relief, not a setback.

Hartmann (1933) later extended the paradigm to obsessive-compulsive functioning. It was an early hint that unfinished tasks might illuminate intrusive, perseverative thought.

Evaluation: Zeigarnik’s design was ahead of its time. Asking about recall unexpectedly meant it tapped spontaneous memory, not deliberate study. Her scoring was partly subjective, though: she counted only responses given before hesitation.

The tasks and interruptions were not standardised either. The result is real. Its size depends on exactly the motivational conditions Zeigarnik herself flagged.

The Ovsiankina Resumption Effect

A related finding follows. It came from the same Lewin laboratory: the resumption effect reported by Maria Ovsiankina (1928). Where Zeigarnik measured memory, Ovsiankina measured behaviour: whether people spontaneously return to finish an interrupted task with no instruction to do so.

The task pulls them back. Participants were given simple tasks, such as puzzles or drawing, and interrupted partway through. The experimenter then created a chance to act freely and recorded, without prompting, whether the person resumed the unfinished activity.

Most did. Resumption was strongest immediately after interruption, and weakened once a substitute activity had partly discharged the underlying need.

Ovsiankina’s finding converges with Zeigarnik’s from a different angle: an interrupted task pulls toward completion, not just toward recall. Because the two findings are logically separable, their agreement is genuine support for Lewin’s tension-system account.

Critical Evaluation of the Zeigarnik Effect

The Zeigarnik effect is a textbook case of a fragile phenomenon. Its reputation has outrun its evidence. It appears reliably only under specific motivational conditions, and modern historical scholarship treats it as genuine but modest, not a universal memory law (MacLeod, 2020).

The Fragile Replication Record

Psychologists generally agree the effect is sensitive to factors that are hard to control in a lab. It is not fixed.

The effect is less likely when a participant feels personally invested in the task. It is more likely when the interruption feels accidental, or when the task still feels achievable (Denmark, 2010).

Zeigarnik only counted responses given before hesitation. She treated that as the portion of recall tied to her tension hypothesis. This idiosyncratic scoring is one reason researchers, beginning with Schlote (1930), have been unsupportive of the effect.

Hovland (1951) went further. He stated bluntly that “few investigators could unequivocally reproduce Zeigarnik’s findings.”

Two later reviews confirmed the problem. Butterfield (1964) concluded the effect is “far from being the invariable result” its popularity implied. Some studies even found completed tasks recalled better, especially when completion signalled success.

Van Bergen agreed. His book-length review of task interruption reached a similarly deflating verdict: the recall advantage was not consistently reproducible once the many moderating conditions were taken seriously.

Moderators of the Effect

The clearest moderator study is Atkinson (1953).

Aim: To test whether the recall advantage for interrupted tasks depends on achievement motivation, the strength of a person’s need to succeed.

Method: Participants completed the usual split of completed and interrupted tasks with an incidental recall test, and were classified by strength of achievement motive.

Results: The pattern was not uniform. High-achievement participants often showed the classic advantage for interrupted tasks, but under some conditions instead recalled completed, successful tasks better.

Conclusion: Atkinson reframed the effect as a function of ego-involvement and motive strength, not a fixed property of interrupted tasks. If direction depends on personality, studies that ignore it will get inconsistent results.

A different moderator came from McGraw and Fiala (1982). They found that offering an extrinsic reward for the tasks made the recall advantage disappear. Once payment became the point of the task, interruption no longer left the same unmet goal behind.

Taken together, the effect weakens or reverses under several conditions.

• Low involvement: trivial, unmotivating tasks generate little tension.
• Relief, not thwarting: an interruption read as permission to stop leaves no tension behind.
• Reward: an extrinsic incentive shifts the goal from completion to payment (McGraw & Fiala, 1982).
• Success framing: when completion signals achievement, completed tasks can be recalled better instead (Atkinson, 1953).

Despite this uneven record, the effect remains widely studied. This includes people with intellectual disabilities and those with obsessive-compulsive disorder. Hartmann (1933) was an early influence on that clinical direction (Heinz, 1997; House & McIntosh, 2000; Mäntylä & Sgaramella, 1997).

Contemporary Research

Recent work has largely stopped asking whether the Zeigarnik effect is true. Instead, it asks what an unfinished task does to ongoing thought and wellbeing.

Plan-Making and Unfinished Goals

Masicampo and Baumeister (2011a) recast Lewin’s tension system as goal activation. An unmet goal keeps intruding on thought until it is closed.

Across several experiments, participants held an unfulfilled goal in mind. Some were then prompted to form a specific plan for completing it, while others were not.

Unfulfilled goals produced more intrusive thoughts and impaired performance on unrelated tasks demanding attention. Making a concrete plan largely eliminated this interference, even though nothing had actually been completed.

The finding sits within the wider ego-depletion and self-regulation programme. Several strands of that programme have faced replication scrutiny, so its effect sizes warrant continued testing.

Unfinished Tasks and Sleep

Syrek, Weigelt, Peifer, and Antoni (2017) followed unfinished tasks out of the lab. A diary study matched 357 Friday-and-Monday observations over 12 weeks for 59 employees.

The pattern was clear. Employees who ended the week with more unfinished tasks ruminated more and slept worse over the weekend.

The damage came specifically from negative, affect-laden dwelling rather than constructive problem-solving. A heavier three-month backlog of unfinished tasks predicted worse sleep impairment still.

Closing an open loop helps. Simply planning how to close it can switch off this intrusive cost too.

Examples of the Zeigarnik Effect in Everyday Life

References

Atkinson, J. W. (1953). The achievement motive and recall of interrupted and completed tasks. Journal of Experimental Psychology, 46(6), 381.

Butterfield, E. C. (1964). The interruption of tasks: Methodological, factual, and theoretical issues. Psychological Bulletin, 62(5), 309.

Denmark, F. L. (2010). Zeigarnik effect. The Corsini encyclopedia of psychology, 1-1.

Hartmann, H. (1933). An Experimental contribution to the psychology of obsessive-compulsive neurosis: on remembering completed and uncompleted tasks.”. Essays on Ego Psychology, 404-418.

Heimbach, J. T., & Jacoby, J. (1972). The Zeigarnik effect in advertising. ACR Special Volumes.

Hiramatsu, Y., Ito, A., Fujii, M., & Sato, F. (2014). Development of the learning system for outdoor study using Zeigarnik effect. Paper presented at the International Conference on Learning and Collaboration Technologies.

House, R. D., & McIntosh, E. G. (2000). The Zeigarnik effect in a sample of mentally retarded persons. Perceptual and motor skills, 90(2), 702-702.

Hovland, C. I., & Stevens, S. (1951). Handbook of experimental psychology.

MacLeod, C. M. (2020). Zeigarnik and von Restorff: The memory effects and the stories behind them. Memory & cognition, 48(6), 1073-1088.

Mäntylä, T., & Sgaramella, T. (1997). Interrupting intentions: Zeigarnik-like effects in prospective memory. Psychological Research, 60(3), 192-199.

Marrow, A. J. (1969). The practical theorist: The life and work of Kurt Lewin. Teachers College Press.

Masicampo, E. J., & Baumeister, R. F. (2011a). Consider it done! Plan making can eliminate the cognitive effects of unfulfilled goals. Journal of Personality and Social Psychology, 101(4), 667-683.

Masicampo, E. J., & Baumeister, R. F. (2011b). Unfulfilled goals interfere with tasks that require executive functions. Journal of Experimental Social Psychology, 47(2), 300-311.

McGraw, K. O., & Fiala, J. (1982). Undermining the Zeigarnik effect: Another hidden cost of reward. Journal of Personality, 50(1), 58-66.

Ovsiankina, M. (1928). Die Wiederaufnahme unterbrochener Handlungen [The resumption of interrupted actions]. Psychologische Forschung, 11, 302-379.

Schlote, W. (1930). Über die Bevorzugung unvollendeter Handlungen: JA Barth.

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.

Van Bergen, A. (1968). Task interruption. North-Holland.

Zeigarnik, B. (1927). Das Behalten erledigter und unerledigter Handlungen [On finished and unfinished tasks]. Psychologische Forschung, 9, 1-85.

Zeigarnik, B. (1938). On finished and unfinished tasks.

Further Information

• McGraw, K. O., & Fiala, J. (1982). Undermining the Zeigarnik effect: Another hidden cost of reward. Journal of Personality, 50(1), 58-66.
• Burke, W. W. (2011). A perspective on the field of organization development and change: The Zeigarnik effect. The Journal of Applied Behavioral Science, 47(2), 143-167.