What’s Unit Cohesion?

And how do you know whether gay soldiers are ruining it?

Soldiers working together in Afghanistan

Our fighting men and women are ready for the repeal of the “don’t ask, don’t tell” policy, according to a Pentagon study released Tuesday. The only potential downside is “some limited and isolated disruption to unit cohesion and retention.” What’s unit cohesion?

The willingness to stick together on a mission. Or something like that: Despite reams of research by military analysts and a general agreement that “cohesion” is important, there’s no consensus definition of the concept. Psychologists have conducted similar studies of cohesion among business colleagues and sports teams, and they can’t agree on a meaning, either. Over the past two decades, most researchers in the field have at least agreed that unit cohesion has two components. Task cohesion is the commitment to working together on a shared goal, while social cohesion refers to the emotional relationships between members of a group. Some psychologists have tried to slice the concept even thinner, distinguishing between horizontal cohesion (bond strength between colleagues) and vertical cohesion (the willingness of subordinates to follow their leaders).


The phrase unit cohesion comes from the 19th century, when engineers used it to refer to the tendency of a material to break apart (or, rather, to not break apart). Military types borrowed the words after Nazi soldiers amazed Allied commanders with their discipline in fighting for a lost cause. But military leaders had long emphasized the idea of group commitment to a common goal. Ancient Swiss soldiers known as the Helvetii burned their own villages before attacking Gaul, so they would have nothing left to fight for but one  another. Seventeenth-century Caribbean pirates punched holes in their boats  as they approached a target, so that the buccaneers would be singularly committed to the mission.

The objective measure of unit cohesion has proved a challenge. Most analysts rely on surveys developed during the mid-1980s with anywhere from 20 to 119 items, which require soldiers to indicate how much they agree with statements such as, “Soldiers like being in this platoon,” “Soldiers in this platoon like one another,” and “Leaders and first-timers in this platoon train well together.” The longer questionnaires also measure the amount of time the unit has worked together with the same commanders.


The results from such questionnaires have startled researchers in a couple of ways. First, despite the Pentagon’s best efforts at team-building, soldiers tend to give their units ho-hum rankings. More important, early studies showed a fairly weak relationship between cohesion and performance. Cohesive units didn’t perform better in battlefield simulations. Eventually, researchers figured out that task cohesion—but not social cohesion—correlates with effectiveness. In other words, the soldiers who were committed to working together ended up being more effective, while the ones who merely got along saw no added benefit. (This is one of the reasons the Pentagon recommends repealing Don’t Ask, Don’t Tell: Its biggest effects will be on social cohesion.)


Why aren’t the chummy combat units more effective? People who get along tend to think alike, and dissenting opinions may be suppressed. Also, some groups become so intent on socializing that they don’t work very hard at improving their performance. They act more like a club than a fighting force.

This doesn’t mean social cohesion is unimportant. Units that get along well are happier, less likely to experience desertions, and better at coping with the psychological stresses of military life.

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Explainer thanks Robert MacCoun of UC-Berkeley.

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