The Zeigarnik Effect

The discovery of the Zeigarnik effect dates back to 1920s Berlin. The Soviet psychologist Bluma Zeigarnik was sitting in a café when she noticed something interesting about the waiters. They could remember extremely complicated orders without writing them down—but only as long as the bill was unpaid. As soon as the customer had paid, the information was erased from the waiters' memory in an instant.

Through laboratory experiments, Zeigarnik confirmed her hypothesis: test subjects who were interrupted in the middle of a task remembered the details of that task up to twice as well as the details of tasks they were allowed to complete in peace. Initiating an action creates a goal-oriented cognitive tension. The brain places the task in a form of temporary working memory and keeps it active until the goal is reached.

From an evolutionary perspective, this is a highly functional mechanism. If our ancestors began a hunt or a construction project, it was vital not to forget the task halfway through. The brain's reminder system ensured that focus was maintained until the goal was achieved.

In today's information society, however, the same system has become a source of constant overload. This is because the brain makes no major distinction between life-and-death tasks and needing to buy milk, send a reply to an invitation, or clean out the storage room. All unfinished projects generate the same type of cognitive loops.

You can use the Zeigarnik effect strategically to defeat procrastination. The threshold for starting a large and difficult task is often high. But if you decide to work on the task for just five minutes, you create an opening. As soon as you have started, the effect is activated, and your brain will naturally strive to finish what you have begun.

For writers and creators, the effect is a powerful tool against writer's block. The author Ernest Hemingway used the method of always stopping writing when things were going best and when he knew exactly what was going to happen next. By leaving the text there, he maintained cognitive tension overnight and could easily step right back into writing the next day.

There is also a method to reduce the stress from too many open loops. Research by psychologists Roy Baumeister and E.J. Masicampo has shown that you do not necessarily have to complete the task itself to calm your brain. It is enough to write down a concrete and reliable plan for *how* and *when* you will complete it. Writing down the next step acts as a temporary closure of the loop, which frees up working memory.

The Zeigarnik effect has a clear dark side. If you accumulate too many unfinished projects at once, cognitive overload occurs. Every open loop draws a small amount of cognitive energy, which in the long run can lead to difficulty concentrating, sleep problems, and chronic stress.

The effect also requires that you actually care about the task or goal. If a task feels completely meaningless or forced, often no cognitive tension is created at all when it is interrupted. The task then simply falls into oblivion without generating any forward momentum.

A common mistake is starting far too many things at once, believing it increases momentum. Instead, this leads to the brain being filled with background noise from dozens of open loops, creating exhaustion rather than progress.

Another mistake is relying entirely on one's own memory to keep track of unfinished tasks. Walking around with mental to-do lists unnecessarily burdens working memory. It is significantly better to let external systems – such as paper or digital lists – take over the storage.

It is also easy to make the mistake of sending messages to colleagues or partners that open unintentional loops. Writing messages like "We need to talk tomorrow" without context opens an extremely strong and stressful cognitive loop in the recipient, creating unnecessary anxiety.