Imagine this: You're a team leader and frustrated because the office kitchen is a mess, and not for the first time.

Do you say, 'Too many people are leaving the kitchen in a mess. Please tidy up before you leave ' or 'Thanks to those who tidy up after using the kitchen'?

The results of many studies suggest that highlighting those who are doing the right thing is likely to be more effective.

Humans tend to follow the most popular action. In one study researchers put leaflets behind the windscreen wipers of cars in a parking building and measured how many leaflets were left as litter. When they 'seeded' the route to the lifts with leaflets, many more people dropped theirs on the floor.

Media campaigns that highlighted littering, or how people don't turn up for their hospital appointments, or fail to vote, have only made things worse.

Accentuate positive examples instead. 'Thanks to all those who've put their reports in on time.' 'Thanks to all those who have already completed the survey.'