The 'Dance' Of Movement: There's A Bit Of Repetition To Avoiding Collision

Ever wonder how we walk between others without running into each other?

New findings published in the Journal of Experimental Psychology: Human Perception and Performance, a journal of the American Psychological Association reveals there is actually a precise pattern in which we avoid collision, almost like a dance.

The study involved 12 pairs of two participant groups who simultaneously moved objects on a 50-inch computer screen from one location to another while holding a hand-held motion-tracking sensor to control their movements and without bumping the objects into one another. These tasks included moving a dot on the computer screen from bottom-left to top-right for one participant and bottom-right to top-left for the partnering participant. 

"This task was chosen because many joint actions involve the continuous production of repetitive movements over time," the study authors noted, in a news release. "For instance, the same or similar movements are performed in a repetitive manner when two individuals are loading a dishwasher, stacking a pile of blocks or magazines, or dancing or (Kung Fu) fighting together. These social activities, however, do not involve the incidental inphase or antiphase movement synchronization that has been the focus of previous studies of social coordination. On the contrary, they require that individuals explicitly avoid colliding into each other and establish a more complex or complementary pattern of movement coordination -- since prototypical inphase or antiphase patterns of movement coordination would result in task failure."

Twenty-four college undergraduates were included in the study, all who were right-handed. The pairs were asked to stand back to back while performing tasks and were not allowed to see each other but could only see their partners virtual dot movement on the screen. A Polhemus FASTRACK magnetic motion tracking system recorded and tracked the movements of each participant.

Researchers found that close to all the pairs seemed to fall into the same stable coordination pattern regardless of their given instructions. Furthermore, the study results showed 164 successful trials completed by the pairs. On average, the 11 pairs retained for analysis took 21 trials to reach a score of 15.

With future studies, researchers believe these could help them better understand how coordination of interpersonal movement may support research in areas ranging from social coordination of certain illnesses, including autism, schizophrenia and other health problems.