"OK, Now for the Boxspring ..."

Moving a couch into a third-story walk-up is one of those everyday miracles that isn’t celebrated nearly enough. The couch is heavy and unwieldy, the staircase is steep and angular, and the banister is always in the way. There is no way you can manage this job by yourself, but the cousin who agreed to help out is surely more trouble than he’s worth. Yet somehow you do it. Grunting, not speaking, often without eye contact, the two of you nudge and jostle and heave and just when the threshold seems impossibly narrow . . . it’s in! A miracle. Next time, before you reach for that cold one, sing hosannas.

Men and their cousins have presumably been performing these feats for centuries, eons probably. But how do we do it? How do we get two complex, independent nervous systems to work together on such a complex task? Northwestern University’s Kyle Reed put together a team of psychologists and engineers to explore this phenomenon in a laboratory, to see how perception and touch combine in everyday acts of cooperation.

The scientists didn’t dare ask volunteers to move a stranger’s couch. They would be unethical. So they simulated that challenge by devising an elaborate task that demanded accurate eye-hand coordination. Basically, they had two participants hold two ends of a crank; they couldn’t see each other or talk, but together they had to manipulate the crank to play a rudimentary video game. They could also do the task alone, which each of them also tried.

The findings, from hundreds of trials, were intriguing. As they report in the May issue of Psychological Science, each of participants worked harder when coordinating with someone else, exerting more force on the crank than when they worked solo. But interestingly, the extra exertion was used to work against the partner, not with him. And the participants sensed this: Some actually complained afterward that the partner was more of an impediment than a help.

Or so it seemed. But in fact this perception was wrong. When the actual times were tallied, the participants consistently did better working together than either of them did working alone. The physical resistance that they felt the other exerting was real, but it was somehow contributing to their shared success. The researchers speculate that the two participants’ physical contact, even though it was by way of a mechanical device, acted as an effective form of communication. They used this tugging and pulling to come up with a cooperative strategy that even they were unaware of.

Now before you break into song, know that none of this will make hauling the next couch up all those stairs any easier. But at least you might have more generous thoughts about your hapless cousin as you struggle to the top.

For more insights into human nature, visit the Association for Psychological Science website at www.psychologicalscience.org.