Yawns are more contagious among family

A study by the University of Pisa (Italy) suggests that people are more likely to yawn in response to the yawn of a close relative to that of a friend or a stranger, according to the journal PLoS One

The act of yawning has always been considered "infectious"because when someone yawns in a group around other people do the same thing by accident. Moreover, this reaction, often in about half the population is not unique to humans, but also exists in animals such as chimpanzees.

For the new study, Italian researchers looked at 109 men and women in a variety of nationalities in their daily activities andrecord the times in which they were yawning contagious. The study found that it was more likely to occur between members ofthe same family, a little less with friends, and even less between simple "known" and strangers.

Furthermore, the time between yawning and imitation responsewas higher among acquaintances and strangers that amongfamilies, which "demonstrates that the contagion of yawns is primarily generated by the emotional closeness between individuals and not by other variables, such as gender andnationality, "the researchers conclude.