Scientists believe they have uncovered the cognitive process that underpins social norms like queuing or holding open a door for somebody.

Researchers at Warwick Business School believe people enter into ‘virtual bargains’ with each other, where they jointly create and follow unspoken agreements.

In papers published in the Philosophical Transactions of the Royal Society and Trends in Cognitive Sciences, a team at Warwick Business School propose a new theory of social decision making - virtual bargaining - in which individuals decide among a set of moves on the basis of what they would agree to do if they could openly bargain.

Nick Chater, Professor of Behavioural Science and co-host of BBC Radio 4's The Human Zoo, said: “When it is obvious what we would agree if we discussed what to do, then we don’t need to bother with the discussion - we just do it! That’s the essence of virtual bargaining.

“Football is a good example, one player runs into space just as the other passes the ball into that space. Though there is no time to talk, players coordinate just as if they had.

“Virtual bargaining starts young. Seeing an adult approaching a cupboard holding a heavy pile of books, a toddler will rush in to open the cupboard door. And virtual bargaining is everywhere. In sport, dance, music or acting people intuitively coordinate with each other in incredibly complex ways. And everyday activities, like two people carrying a table up a flight of stairs involve amazingly subtle coordination, with only minimal communication.”

An experiment using a simple game reveals the process of virtual bargaining. Two players, without communicating to each other, must choose either Hi or Lo. If they both choose the same they receive a reward, but the reward is bigger if they both choose Hi. It is obvious they will both choose Hi, but explaining why is not easy.

“According to many economists and psychologists, people will choose by trying to figure out what the other person will choose,” said lead researcher Jennifer Misyak. “But in the Hi-Lo game, this takes us round in a circle: I want to choose whatever you choose; and I know that you want to choose whatever I choose; but the question of what I should choose is the problem we started with!

“Virtual bargaining shows how people break out of the loop: by imagining what they would agree if they could communicate. If both players could talk, they would obviously agree to play Hi and get the bigger prize. But because this is ‘obvious’ they don’t need to talk, they just go right ahead and do it.”

Social norms, like joining the back of the line at a supermarket till or one person holding the door open for another, have arisen because of past virtual bargains.

Professor Chater said: “Each new bargain is based on a ‘precedent’ for determining future bargains. This layering of bargains creates the unwritten rules that help us navigate complex daily interactions. Many of these rules can be quite arbitrary like shaking hands or waving goodbye; but once established, we follow them automatically.

“Virtual bargaining provides a starting point for thinking about how rules, norms, customs and conventions emerge spontaneously through incremental layering of successive bargains - in short, why we queue, and why we get cross when other people don’t! It illustrates how we are able to follow an inordinately elaborate set of rules without consulting any rule book."

Professor Nick Chater teaches Behavioural Sciences for the Manager on the Warwick Executive MBA and Behavioural Science and Leadership for Executives plus Principles of Cognition on the MSc Business. He also teaches Emotions in Business on Warwick Business School's Undergraduate courses.