It might sound counterintuitive, but keeping busy is the key to completing tasks that would otherwise get abandoned, a massive new study has found - especially if you've already missed a deadline.

The research, based on five different studies covering thousands of people, focused on how to keep our motivation up when we realise we can't get everything done on time, and found that the sense of failure we feel when missing a deadline is key. For those of us who stay busy and keep working, that shame is less prominent, and that means we're more likely to go back and finish something even if it's late.

But if your schedule is not super-packed and you missed your deadline anyway, that feeling of guilt combined with a lack of motivation means you're more likely to abandon whatever it is that needed to get done. 

Three of the studies the team from Columbia University analysed were based on a simple survey asking participants to identify a failed task from the last week and think about how much they had on their plate at the time. They were also asked how motivated they were to complete the task now, and in some cases, were told to report back if they managed to tick it off their 'to do' list seven days later.

Another study involved a group of students who were paid to complete an online survey. Of the 24 students who didn't do as they were asked within the designated two-day timeframe (27 percent of the group), those who were busier were found to be more likely to go back and follow up on the task after the deadline had passed.

The researchers also looked at data gathered from 28,800 people over the course of 18 months. According to the behaviour logged in a task management app, those with hectic schedules were more likely to push back their deadlines, but were also more likely to eventually complete the tasks that had been delayed.

"This effect occurs because busy people tend to perceive that they are using their time effectively, which mitigates the sense of failure people have when they miss a task deadline," concludes the report, published in the Journal of Personality and Social Psychology.

So if you're short on time, as long as you're using it effectively, it'll do wonders for your motivation, even if you end up with way more on your plate than you can actually manage. 

And if you want to get the highest productivity scores in the office, start taking on more work: you might miss more deadlines, but you'll eventually get more done, and feel pretty awesome doing it.