How does an audience know when to start and stop clapping?

Researchers have found that applause spreads like a 'disease’ though an audience, with applause duration often not connected to the quality of the performance, as reported in Journal of the Royal Society Interface today.

Swedish Uppsala University scientists investigated how applause starts and subsequently stops in an audience, to test theories of how behaviours spread socially in human groups. They found that applause can spread like a ‘disease' through the group. Individuals appear to pick up the clapping ‘infection' by hearing the volume of applause, rather than directly seeing their neighbours clapping. The group will only stop once at least one individual decides alone that they have clapped for long enough. The variability in this individual decision means that the applause duration is often not connected to the quality of the performance.

Lead researcher Dr Richard Mann and his colleagues filmed the response of six different groups of 13–20 university students to two different oral presentations. They found that an individuals’ probability of starting clapping increased in proportion to the number of other audience members already ‘infected’, regardless of their spatial proximity.

The cessation of applause is similarly socially mediated, but is to a lesser degree controlled by the reluctance of individuals to clap too many times. They also found consistent differences between individuals in their willingness to start and stop clapping. The researchers thus concluded that applause can be modelled as a ‘social contagion’. According to this model, the time the audience spends clapping can vary considerably, even in the absence of any differences in the quality of the presentations they have heard.