Did you know that a task that’s interrupted takes 50% longer and has 50% more mistakes than an uninterrupted one?
It takes a while for our brains to get into a focused state where we’re able to concentrate fully on a task without feeling distracted. Once we’re in that state, we can enjoy a very productive flow, as long as we don’t get interrupted.
A focused mind is still sensitive to disruption from external input. Interruptions — i.e. switching to a different, largely unrelated set of thought patterns — erase and scramble much of your previously loaded and nicely optimized brain state. And frequent interruptions can prevent you from ever fully entering that state of flow.
When you interrupt someone, on average it takes them 23 minutes to get back to the original task, plus up to 30 minutes to return to the flow state so they can be fully productive again. Almost half of the time you interrupt someone, you’ll actually knock them off task completely, such that they won’t return to the original task right away when the interruption ends. You may think you’re only putting them on pause for a minute or two, but the actual break from the task that results from your interruption may be significantly longer.
About 80% of the time when a task is interrupted, the person will return to it that same day, but roughly 1 out of every 5 times you interrupt someone, you’ll actually cause them to stop all work on that task for the entire day.
Have you ever been briefly interrupted by someone, only to extend that interruption by concluding that since you’ve already paused working, you might as well go to the bathroom now, check email, have lunch, etc? How many times has a quick question turned into a lengthy conversation? These are common experiences, especially among knowledge workers. A seemingly minor interruption can derail your focus so much that it takes hours to get back to the original task, if you even get back to it that day.
Frequent task switching has also been measured to significantly increase stress levels vs. single handling. So interrupting others not only hurts their productivity, but it may also damage their health.
Interruptions are expensive too. One estimate puts the cost of workplace interruptions at $588 billion per year in lost productivity for the U.S. economy. This is probably a gross underestimate though since it’s only based on wasted hours multiplied by average wages. It doesn’t consider the rippling consequences of these interruptions, including missed opportunities, lost sales, layoffs, businesses going under, reduced investments, costly mistakes, more sick days due to increased stress, etc. Interruptions mean that some books are never finished, some businesses are never launched, and some ideas are doomed to die on the vine.
The next time you think about interrupting someone who’s productively working on a task that’s important to them, consider that your seemingly innocent question or comment may create serious consequences for them, including adding more work to their plate, increasing their stress, causing mistakes, creating delays, and potentially killing the task completely. Even a brief interruption of a complex task can create the cognitive equivalent of an hour of extra work.
Highly productive people know the importance of working in uninterrupted blocks of time with good focus and concentration. Consequently, they take steps to guard against interruption, such as by wearing headphones to discourage trivial conversation (even if no audio is playing), by closing their office doors, by cautioning others not to interrupt them unless absolutely necessary, by letting people know when it’s okay vs. not okay to chat with them, by working in different locations, by turning off phones and notification services, or by working different hours.
Many programmers, for instance, love to work late at night. One reason is that they’re less likely to be interrupted while everyone else is sleeping, so their nighttime work can be more productive. Online activity (email, social media, etc) also tends to drop off significantly late at night.
Being social is fine. But if someone is actively working, let them keep working. You can talk to them when they’re done.
If you have issues with other people interrupting you more than you’d like, ask them to use the following rule of thumb (or any other guideline that satisfies you):
When I’m busy working, please don’t interrupt me unless what you have to share is so urgent and important that it’s worth erasing all the work I’ve done in the past hour.