What the juggling costs

You may think of the habit as costing a bit of efficiency. Most of this chapter is my own reckoning, and I'll say where a study comes in.

Time. Every restart takes minutes, and you pay for dozens of them a day. I can't give you a percentage for your job, and I distrust the round figures that circulate. Your tally sheet and a stopwatch will give you your own.

Mistakes. Altmann's three-second interruptions doubled the rate of lost-place errors. In your work those turn up as a figure copied into the wrong row, an attachment you forgot, or an email sent to the wrong Sarah. They tend to be found later, by someone else.

The important work. Anything needing sustained thought gets done badly or late, because it's the most vulnerable to interruption. Over years, this shapes a career. Someone can be known as wonderfully responsive and never quite deliver the big pieces.

Your evenings. The work that didn't get finished between nine and five goes home in the laptop bag. Many people who think they have too much work have, in part, a working day that produces too little.

Tiredness and stress. Mark's experiment found that interrupted people felt more stress, frustration, time pressure and effort for the same output. A good deal of your tiredness at ten past five came from working this way, over and above the work itself.

The pile in your head. Masicampo and Baumeister's unfinished goals intrude on whatever else you're doing. With six things open, you're carrying all six through every meeting and half the evening. It's part of why you can't switch off at home.

Other people. Someone is waiting for each half-done thing. The supplier is waiting for the email. Priya can't start her part until she has section two. At home, nobody can put books on the shelf yet.

The people in front of you. When you half-listen to a colleague while reading a message, they can tell. It's more obvious still to a child who's telling you about their day while you look at your phone. Attention is one of the main ways we show people they matter, and if it's divided they get less of it.

Satisfaction. Finishing something is one of the most dependable pleasures of work. A juggled day contains almost none of it. Sixty small replies don't add up to the feeling of sending off a finished report, and you go home with nothing you could point to.

Against all that, juggling gives you a feeling of keeping up and a reputation for quick replies. It also lets you leave whenever a task gets hard.