The Zeigarnik Effect, Planning Fallacy and Scheduling

Bluma Zeigarnik

When human beings generate time demands in order to fulfill their goals, they create an immediate problem for themselves.

It was first described by Russian researcher, Bluma Zeigarnik. The phenomena which bears her name is easy to understand: our mind, being distrustful of our ability to recall a particular time demand at the right moment in the future, intrudes on our thoughts. It sets up an internal, nagging reminder which repeats itself until the action is complete. In other words, it’s a part of our subconscious which continuously pings our conscious minds.

The Zeigarnik Effect probably isn’t an issue when we are young, having only  a few time demands to complete at any given time. However, a fully matured adult has no such luxury. Instead, people report feelings of information overwhelm when their mind becomes a restless source of seemingly random intrusions.

Ed Masicampo

Before the work of Ed Masicampo and Roy Baumeister, there was no known way to rid oneself of the Zeigarnik Effect, aside from completing the task. However, their 2011 research confirmed a feeling that we have, perhaps, all experienced. The nagging feeling goes away when our time demands are  properly managed.

Here at Schedule U, we consider this recent finding to be all-important. It gives us an important clue for those who would manage a large number of tasks of tasks – the only way to avoid the unwanted feelings of overwhelm is to manage your time demands effectively.

Roy Baumeister

The researchers put it well: “Planning has been studied recently in the form of implementation intentions” and “Once a plan is made, the unconscious knows how and when to act, and so in a sense the uncertainty of the unfinished task is resolved.”

Peter Gollwitzer

The notion of an implementation intention which they use was pioneered by Peter Gollwitzer. Masicampo and Baumeister define them as “highly specific prescriptions for what to do under what circumstances (Gollwitzer, 1999). Such plans turn control of goal pursuits over to automatic, unconscious processes, which can resume goal pursuit at the appropriate time or place specified in the plan.”

In general, implementation intentions are an effective part of what psychologists call “prospective memory.” It’s easier to define by its opposite, “retrospective memory”, which is the memory we use to store items in the past. For example, your lunch meal yesterday is part of this memory.

Prospective memory includes all time demands, plus your intentions for the future. For example, your plans for your next meal form part of this memory.

Angela Conte

They exist in two varieties, according to Angela Conte: time-based prospective memory is remembering to retrieve a future intention at a particular time/date, while event-based prospective memory involves the use of a specific cue or event.

The former are more difficult to manage because they involve proactively watching the clock in order to synchronize an action with a particular moment in time. Unfortunately, each tiny glance is an interruption which represents a loss of effectiveness.

The Planning Fallacy

Sander Koole

Implementation intentions serve another important purpose in addition to reducing the Zeigarnik Effect. They reduce the planning fallacy – the human tendency to miss due dates because of poor scheduling.

In their 2000 paper, Sander Koole and Mascha Van’t Spijker showed that implementation intentions are effective tools in reducing the planning fallacy.

Mascha Van’t Spijker

In their experimental study, participants who used implementation intentions were more likely to complete their planned tasks. They also reduced the “optimistic bias” which plagues so much planning.

They also found that these same participants gave more optimistic completion predictions – a possible recipe for disaster. However, the researchers showed that “this increase in optimism was exceeded by an increase in actual rates of goal completion due to forming implementation intentions. The net result… was…a reduction in unfounded optimism.”

Furthermore, they discovered that the formation of “implementation intentions led to a smaller number of interruptions during action execution.” In this case, they are referring to outside interruptions – from colleagues, or a ringing phone, for example. They theorized that implementation intentions help someone “mentally seek out environments where task completion will not  be disturbed” in a form of “shielding function.”


In 2012, Amy Dalton and Stephen Spiller went in search of some answers to a problem plaguing researchers of the ideas shared on this page. Their article

Amy Dalton

entitled “Too Much of a Good Thing: The Benefits of Implementation Intentions Depend on the Number of Goals” showed that the benefits of the technique to single goals do not typically extend to multiple goals.

Instead, they argued, trying to extend the technique to multiple goals “drew attention to the difficulty of executing multiple goals”, thereby undermining commitment.

However, in a finding similar to that of Baumeister and Masicampo’s, a transformation appears to occur when the execution of multiple goals is framed as a manageable endeavor. In an experiment, Dalton and Spiller led a group of subjects to believe that managing multiple goals would be easier. This framing made all the difference and increased goal completion.

They also cited research showing that “people with

Stephen Spiller

multiple goals are more successful if they think their goals are working together to help fulfill a common purpose.”

They are careful to mention that none of the goals in their study were particularly difficult. Instead, the challenge arises from time and resource constraints: “When people juggle multiple goals, completing one task means neglecting or postponing others, which reduces the expected likelihood of ever achieving all goals.”

A very different 1981 study led by Daniel S. Kirschenbaum compared two groups of students: one which created daily plans versus another which made monthly plans. Those latter outperformed the former. At first blush, it appears to indicate a problem with Total Task Scheduling, which is much closer to the daily planning technique taught in the study.

However, the design of the study indicates why these results were realized. Each group was randomly assigned so that the much more difficult, unfamiliar technique of daily planning was assigned in the same way as monthly planning. If we were to conduct a similar experiment today among average adults we would probably see the same result.

The fact is, Total Task Scheduling isn’t for everyone, and it’s much harder to implement. The researchers suggested that the designated daily planners were overburdened with the task of planning each day which also caused “negative affective reactions” in participants who failed to meet their daily targets.  As a result, daily planners quit reporting study results after only the first of three months.

The lesson is that forcing people to make daily plans doesn’t work. Perhaps it also sends a warning: when trying to adopt a new technique like daily planning it’s much harder than using a familiar technique. At Schedule U, I recommend that the best improvement for you to make is a baby step from your current set of habits, practices and rituals. It’s a principle I use in my book and also in A Course in Scheduling.


In the words of Koole and Van’t Spijker, implementation intentions allow someone to “have one’s cake and eat it too.” Instead of teaching people to temper their expectations because it’s easier than boosting one’s effectiveness, they should be taught to use implementation intentions.

Earlier we discovered that they also reduce the nagging feelings of overwhelm described by the Zeigarnik Effect.

These are powerful benefits which can accrue to Total Task Schedulers who master the management of implementation intentions.

However, people who are unable to create a reliable system may find scheduling all their time demands to be an impossibility. This may explain why so many have failed and why it pays to adopt a slow but steady approach to adopting the new technologies which are now available.

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