Maria Nieves and Juan Carlos Copes are passionate about Argentine tango. They have been dancing together for 40 years and are among the best-known dance pairs in the world. Copes was once heard to say that if he had not found Nieves--someone to whom he is remarkably attuned--he would need four different partners to fully explore the tango's expressive spectrum. Anyone who has ever done pairs dancing will understand just how difficult it is to forge a merger out of differing styles and capacities, while coordinating movements with near perfection in space and time.
These coordination problems fascinate researchers who study cooperation. Whereas Copes and Nieves have learned to harmonize their movements to an extraordinary extent, it is clear that ordinary people are constantly attuning to one another, even during the most mundane daily activities. We set the table together, carry a large package or navigate between other drivers in heavy traffic. As Harvard University social psychologist Floyd Henry Allport recognized more than 80 years ago, such daily acts of cooperation are anything but trivial. In the end, two or more persons must coordinate and fine-tune their thoughts and actions. And, unlike dancers, we often have no opportunity to rehearse this choreography.