Multitasking doesn't make you as productive as you'd think

Jackson Lu and colleagues at Columbia University asked participants to complete tasks involving convergent thinking, problem solving, experiment 1, and divergent thinking, idea generating, experiment 2.

Some were instructed to work on one task in the first half of their allotted time and then switch to a second task. Others were told to alternate between tasks at preset intervals and the third group were allowed to switch between tasks at their discretion.

Those who alternated between tasks at set intervals outperformed everyone else.

Yet when asked which approach they preferred, most said they would choose to switch between tasks at their own discretion, presumably because they feel it gives them maximum autonomy and flexibility.

But the researchers argue that few of us recognise when we're becoming cognitively "fixated"; when our thinking is becoming "stuck".

The best way to overcome this rigidity, they suggest, is to switch between tasks at regular, preset intervals. Regular switching encourages us to look at a task from new angles, making it easier to generate fresh ideas.

Lu's findings are not without precedent. Steven Smith and colleagues at Texas A&M University asked participants to list as many examples as possible of two different categories.

Participants who switched regularly between the two categories generated more solutions than those who completed one category listing and then switched to the second.

It's important to distinguish switch-tasking from multitasking. Switch-tasking means we deliberately alternate between problems; when we multitask we fool ourselves into thinking we're doing several things at once. But we're actually switch-tasking every few milliseconds rather than at longer, predetermined intervals, and as a result our performance deteriorates. - The Daily Telegraph

• This article was originally published in The Times.