If you want to strike up a new relationship, simply smile. It works because people are much more attuned to positive emotions when forming new bonds than they are to negative ones such as anger, contempt or sadness. Don't try to fake it, however, because people can recognize a sincere smile a mile away. This is according to a study led by Belinda Campos of the University of California, Irvine, in the US that sheds light on how relationships are formed and maintained. The findings are published in Springer's journal Motivation and Emotion.

Campos' team conducted two studies to test the role that positive emotions, which are considered signals of affiliation and cooperation, play in relationships. The first one tested how aware 66 dating couples were of their partners' positive emotions. The testing took place while the couples were being teased or were discussing past relationships. The second experiment looked at how attuned people are to positive emotions and if it helps them to form new social bonds. This was done by assigning 91 women to watch six emotionally laden film clips in the company of either a roommate or a stranger..

The first study showed that dating couples were able to quite accurately track their partners' positive emotions. In the second, people tended to feel closer to strangers who displayed positive emotions. The results showed that people are much more aware of others' positive emotions than their negative ones. Also, when finding themselves in situations where new relationships can be formed, humans tune into the positive almost instinctively. A display of awe especially draws strangers to one another.

Furthermore, Campos explains that people predominantly display positive emotions by giving a so-called Duchenne smile. This distinct smile involves the simultaneous movement of two facial muscles around the eyes and cheeks, and is primarily produced when people are sincere and happy. It is seen as a reliable sign of true affiliation and willingness to cooperate with another person, and helps to strengthen social bonds. She believes that people are very much aware of its presence or absence during conversations, and that they are good at "reading" a fake smile.

Awareness of others' positive emotions may provide important relationship information. In a new relationship, for instance, it can help one feel secure about a partner's love, and help resolve conflicts by providing a reason to give a partner the benefit of the doubt. However, it can also mean that you more easily pick up on a partner's shifting attention, which might lead to fear and the chances of a relationship dissolving.

"Our findings provide new evidence of the significance of positive emotions in social settings and highlight the role that positive emotions display in the development of new social connections. People are highly attuned to the positive emotions of others and can be more attuned to others' positive emotions than negative emotions," says Campos.