Try this: when you are in a crowded room, yawn and see how will be other people reactions.
If most people in the room yawn, don't worry, they're not trying to imitate you. This
chain reaction has an explanation.
According to Débora Hipólide, from Universidade Federal de São Paulo (Unifesp), the yawn is a primitive way of comunication to tell the group peers that the weather is about to change. The contagion was usually understood as message receivement, in other words, your peers got the message.
To some vertebrate ancestral, it was the yawn that meant "attention, predator around", " it's about to rain" or "it's bed time". Moreover, in the period, the yawn was often responsable for synchronize the action.
Oliveira, from Unifesp, highlights that a well renowned theory explains that the fault is on the mirror neurons. The cells record our behavior in front of some situations. Our future behavior will be based on these cells memory.
Resource:
http://noticias.terra.com.br/educacao/voce-sabia/por-que-o-bocejo-e-quotcontagiosoquot,e018c087e60ea310VgnCLD200000bbcceb0aRCRD.html
http://mundoestranho.abril.com.br/materia/por-que-quando-uma-pessoa-boceja-a-outra-boceja-tambem
