Peer pressure drives applause: You clap, I clap.

If you have just seen a play that you privately think is drivel, will you keep silent when everyone around you demands an encore? Possibly not, says an unusual investigation published Wednesday in the Journal of the Royal Society Interface. Combining a psychological experiment and mathematical analysis, the research marks a scientific attempt to quantify the fuzzy notion of "social contagion" - how individual behaviour is influenced by group dynamics. A research video taped groups of university students as they responded to a seven minutes Powerpoint presentation. Neither the students nor the presenters knew the applause was being analysed. The results were revealing. People in the audience didn't make an independent told AFP by email. Instead they responded very predictably to the social pressure around them, which is believed they felt through the volume of clapping in the room. As more people started clapping, each individual who hadn't started felt more pressure to join in, the statistics showed.