Stress & Calm
Being Interrupted Costs More Than The Interruption
The expense of an interruption is the reconstruction of context afterwards, which is why brief interruptions can remove far more time than their own duration.
A two-minute interruption rarely costs two minutes. The bulk of the cost sits in what happens after it, and that is what makes fragmented days so unproductive.
Complex work is held in working memory
Anything involving several connected parts requires holding those parts simultaneously: where the argument was going, what has been tried, and what depends on what.
That assembly is fragile and does not persist. It has to be actively maintained, and it decays quickly once attention moves elsewhere.
An interruption dismantles it. Returning means rebuilding, which involves rereading, retracing and reconstructing until the whole picture is available again.
Reconstruction takes longer than it seems
People notice the moment they resume and count from there. The period of partial engagement afterwards, while the work is being reassembled, is not counted at all.
For demanding work that period can be several times the length of the interruption itself. For simple work it is negligible, which is why the effect seems inconsistent.
This explains why the same number of interrupted hours produces very different amounts of output depending on the task.
Anticipated interruptions cost even when they do not happen
Knowing an interruption is possible changes how work is approached. People avoid starting anything that would be expensive to abandon.
The half hour before a meeting is often spent on shallow tasks for this reason. The time is available and the depth is not.
This is why the arrangement of a day matters as much as its total free time. Four fragments of an hour are not equivalent to four continuous hours.
Self-interruption follows the same mechanics
Checking a message or switching to another task has the same effect as an external interruption, and it is far more frequent.
It is also driven by discomfort. Difficult work produces a moment of resistance, and switching away resolves that moment immediately.
The practical countermeasure is removing the switch rather than resisting it, since resisting requires a decision every time and removing requires only one.
Consolidating rather than eliminating
Interruptions cannot be abolished and much of the time should not be. Colleagues and family have legitimate claims on attention.
What can be changed is when they arrive. Gathering them into predictable periods leaves other periods genuinely clear, which is the arrangement demanding work needs.
Leaving a note about where the work stopped also shortens the reconstruction. It is a small habit that recovers a disproportionate share of the loss.
Questions readers ask
Is it healthier to let anger out than bottle it up?
Those are not the only two options; the evidence generally favours neither venting nor suppression, but interrupting the rehearsal and returning to the issue once settled.
Why do small things set me off when I am tired?
Sleep loss reduces the regulatory capacity that normally holds an initial surge in check, so the same trigger produces a larger and faster reaction.
