Person recognition from dynamic events: the kinematic specification of individual identity in walking style

Three experiments used Johansson’s [Perception and Psychophysics, 14, 201–211 (1973)] point-light technique to investigate, whether observers could correctly recognize others from their natural and deceptive walking styles based solely on the kinematic pattern produced when walking. Participants watched pairs of video-clips of unknown young male actors and judged whether the video-clips in each pair were from the same actor or not. The pairs of video-clips consisted of one clip of an actor walking naturally across a room and one clip of an actor attempting to walk deceptively (attempting to make themselves appear considerably older than they actually were). The results from Experiments 1a and 1b demonstrated that participants were fairly accurate at recognizing when the actors in the two video-clips were the same and when they were different. In addition, an invariant of walking style (weight shift) was shown to be an important kinematic feature for the identification of walkers. Experiment 2 demonstrated that those walkers whose weight shift differed between their natural and their deceptive walk were more effective in deceiving observers about their true identity than those whose weight shift was the same in the two walks. The results are discussed in relation to the kinematic specification of identity, and the production and perception of deceptive intent.