LINDA WERTHEIMER, HOST:
We've all been to concerts and performances that bring us to our feet in wild applause.
WERTHEIMER: But what makes us clap more for some performances than others? You'd think it's obvious: the better the show, the more applause. Think again. New research at Uppsala University in Sweden has revealed that applause spreads through a crowd more like a contagion than a reaction to a performer. Researchers watched audience members respond to academic talks - talks even as dull as this one.
UNIDENTIFIED MAN: Put your hand down somewhere on this board, calculate from that the probability that you'll put the pen down in some set of points on this board. This gets you into horrible mathematical complications and paradox.
WERTHEIMER: And they found there's little relation between the quality of a performance and the amount of applause that follows it. It's more a question of what everyone around you is doing. Richard Mann is the lead researcher at Uppsala University.
RICHARD MANN: Our principal finding was that clapping is indeed socially driven so people feel the social pressure to begin clapping if others in the crowd are already clapping. And likewise to stop clapping if others have stopped.
WERTHEIMER: In short, the more people you hear clapping the more likely you are to clap.
MANN: One of the surprising findings we had was that the clapping doesn't spread spatially. So, people aren't mimicking what their direct neighbors are doing in the crowd. Instead, it seems to be the volume of the clapping in the room that spreads the applause. So, as soon as people can hear that other people in the audience are clapping, they begin to clap themselves. So, often you are feeling social pressure from audience members you couldn't directly see.
WERTHEIMER: But what about that first person who puts their hands together? The study found someone that initiates applause in one talk was likely to start it again in the next.
MANN: There are some individuals who are more naturally bold or eager than others, so they tend to be the ones who clap first and often that feeds the future clapping of everyone else.
WERTHEIMER: But most of us just follow what we hear.
(SOUNDBITE OF SONG, "CLAPPING SONG")
SHIRLEY ELLIS: (Singing) Three-six-nine, the goose drank wine, the monkey chew tobacco on the streetcar line. The line broke, the monkey got choked and they all went to heaven in a little rowboat. Clap-clap, clap-clap, clap-clap, clap-clap. Clap-clap, clap your hands, pat it on your partner's hand, the right hand. Clap-clap, clap your hand, cross it with your left arm, pat your partner's left palm. Clap-clap, clap your hand, pat your partner's right palm with your right palm again. Clap-clap, clap your hands, slap your thigh...
WERTHEIMER: This is NPR News. Transcript provided by NPR, Copyright NPR.