The Ringelmann effect was originally studied by having a team of people pull on a rope, measuring each individual's effort. Generally, people pulling the rope b

The Ringelmann effect was originally studied by having a team of people pull on a rope, measuring each individual's effort. Generally, people pulling the rope by themselves exerted more effort than when they were pulling with a team. Later studies by Bibb Latane proved that the effect was not attributable to communication overhead: subjects blindfolded and fitted with sound-proof headsets were asked to shout and clap; people who believed they were performing in a group clapped softer than when they believed to be alone, even if there was no actual group in the room with them. Generally, social loafing is attributed to the feeling that an individual's efforts make little difference to the end result, although I don't believe there are actual studies that could empirically back that up.