In psychology, the Zeigarnik effect states that people remember uncompleted or interrupted tasks better than completed tasks. In Gestalt psychology, the Zeigarnik effect has been used to demonstrate the general presence of Gestalt phenomena: not just appearing as perceptual effects, but also present in cognition.
Psychologist Bluma Zeigarnik first studied the phenomenon after her professor, Gestalt psychologist Kurt Lewin, noticed that a waiter had better recollections of still unpaid orders. However, after the completion of the task – after everyone had paid – he was unable to remember any more details of the orders. Zeigarnik then designed a series of experiments to uncover the dynamic facts underlying this phenomenon. Her research report was published in 1927.
The advantage of remembrance can be explained by looking at Lewin's field theory: a task that has already been started establishes a task-specific tension, which improves cognitive accessibility of the relevant contents. This tension that has formerly been established is being relieved upon completion of the task. In case of task interruption the reduction of tension is being impeded. Through continuous tension the content is easier accessible and it can be easily remembered.
The Zeigarnik effect suggests that students who suspend their study, during which they do unrelated activities (such as studying unrelated subjects or playing games), will remember material better than students who complete study sessions without a break (McKinney 1935; Zeigarnik, 1927).
The Zeigarnik effect should not be confused with the Ovsiankina effect. Maria Ovsiankina was a colleague of Bluma Zeigarnik who investigated the effect of task interruption on the tendency to resume the task at the next opportunity.
The reliability of the effect has been a matter of some controversy. Several studies attempting to replicate Zeigarnik's experiment, done later in other countries, failed to find significant differences in recall between finished and unfinished (interrupted) tasks (e.g. Van Bergen, 1968). It seems that the effect depends on additional factors, most above all on the importance of the interrupted task for the person.
- cf. Kurt Koffka, Principles of Gestalt Psychology, 1935, pp 334ff.
- Zeigarnik 1927: Das Behalten erledigter und unerledigter Handlungen. Psychologische Forschung 9, 1-85.
- Kurt Lewin, A Dynamic Theory of Personality, 1935, pp 243ff
- Ovsiankina 1928: Die Wiederaufnahme unterbrochener Handlungen. In: Psychologische Forschung 11(3/4), 302–379.
- Einstein, Gilles O.; McDaniel, Mark A.; Williford, Carrie L.; Pagan, Jason L.; Dismukes, R. Key (2003). "Forgetting of intentions in demanding situations is rapid." (PDF). Journal of Experimental Psychology: Applied 9 (3): 147–162. doi:10.1037/1076-898X.9.3.147.
[...] there is controversy regarding the reliability of the Zeigarnik effect [...]
- Zeigarnik, B. (1927). Das Behalten erledigter und unerledigter Handlungen. Psychologische Forschung, 9, 1-85. Translated in English as:
Zeigarnik, B. (1967). On finished and unfinished tasks. In W. D. Ellis (Ed.), A sourcebook of Gestalt psychology, New York: Humanities press.
- Denmark, Florence L. (2010). "Zeigarnik Effect". In Weiner, Irving B.; Craighead, W. Edward. The Corsini Encyclopedia of Psychology (4th ed.). John Wiley & Sons. pp. 1873–1874. doi:10.1002/9780470479216.corpsy0924. ISBN 9780470170236.