According to researchers in the UK people behave in a more honest fashion when they think they are being watched.
In an interesting experiment a team from Newcastle University found people put nearly three times as much money into a canteen 'honesty box' when buying a drink, when they were being watched by a pair of eyes on a poster.
They believe such strategies could help when it comes to tackling anti-social behaviour.
The eyes it seems were more effective than a poster that featured an image of flowers and raises the possibility that people are encouraged to behave more co-operatively or pro-socially by putting up pictures of eyes.
The researchers believe this is because the brain naturally reacts to images of faces and eyes and people were subconsciously cooperating with the honesty box when it featured pictures of eyes rather than flowers.
They say the findings illustrate how people behave differently when they believe they are being watched because they are worried what others will think of them.
Being seen to co-operate is a good long-term strategy for individuals because it is likely to mean others will return the gesture when needed.
The experiment is thought to be the first to test how cues of being watched affect people's tendency for social co-operation in a real-life setting and an honesty box is a good way of testing this.
In the experiment, lead researcher Dr. Melissa Bateson and her colleagues Daniel Nettle and Gilbert Roberts, of the Evolution and Behaviour Research Group in the School of Biology and Psychology at Newcastle University, made use of a long-running 'honesty box' arrangement.
The honesty box had been operating as a way of paying for hot drinks in a staff common room used by around 48 staff for many years, so users had no reason to suspect an experiment was taking place.
Above the honesty box, an A5 poster was placed placed at eye-level, which listed the prices of tea, coffee and milk.
The poster also had an image banner across the top, and this alternated each week between different pictures of flowers and images of eyes.
Although the eye pictures varied in the sex and head orientation all were chosen so that the eyes were looking directly at the observer.
Over the course of 10 weeks a record was kept each week by the research team of the total amount of money collected and the volume of milk consumed as this was considered to be the best index available of total drink consumption.
The team then calculated the ratio of money collected to the volume of milk consumed in each week and found that people paid 2.76 times as much money when the notice featured a pair of eyes as opposed to when the image was of flowers.
Lead author of the study, Melissa Bateson, a Royal Society research fellow based at Newcastle University, says the team was surprised by how big the effect was.
They had apparently been expecting to see quite a subtle difference but the statistics showed that the eyes had a strong effect on the tea and coffee drinkers.
Dr. Bateson, a behavioural biologist, believes the findings could apply to initiatives to curb anti-social behaviour or in law enforcement, such as in payment for public transport, road safety or the more general issue of behaviour in public places.
Dr. Bateson says it appears that people are less likely to be selfish if they feel they are being watched, which has huge implications for real life.
The research team now hopes to expand the study to involve a larger sample population.
The research is published in the current issue of the Royal Society journal Biology Letters.