Praxis, demonstration and pantomime: a motion capture investigation of differences in action performances

A commonly held assumption is that demonstration and pantomime differ from ordinary action in that the movements are slowed down and exaggerated to be better understood by intended receivers. This claim has, however, been based on meagre empirical support. This article provides direct evidence that the different functional demands of demonstration and pantomime result in motion characteristics that differ from those for praxic action. In the experiment, participants were dressed in motion capture suits and asked to (1) perform an action, (2) demonstrate this action so that somebody else could learn how to perform it, (3) pantomime this action without using the object so that somebody else could learn how to perform it, and (4) pantomime this action without using the object so that somebody else could distinguish it from another action. The results confirm that actors slow down and exaggerate their movements in demonstrations and pantomimes when compared to ordinary actions.