Unit cohesion is defined by Slate's Brian Palmer as "The willingness to stick together on a mission" with a component of "Task cohesion ... the commitment to working together on a shared goal." Palmer points to studies which showed that task cohesion was more important than social cohesion:
- "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."
Major Geoff Van Epps attempts to clarify the distinction between unit cohesion and teamwork:
- Teamwork is the collaboration or coordinated effort of a group of soldiers toward common goals or objectives. Cohesion, on the other hand, is both more abstract and more basic. Cohesion means a bonding together of an organization or unit’s members in such a way as to sustain their will and commitment to each other, the group, and the mission. Cohesion binds an organization together and enables it to function as a unified, integrated unit. Cohesion allows teamwork to occur under difficult conditions.
Sigmund Freud wrote about what happens to a military unit when its cohesion breaks down:
- A panic arises if a group of that kind becomes disintegrated. Its characteristics are that none of the orders given by superiors are any longer listened to, and that each individual is only solicitous on his own account, and without any consideration for the rest. The mutual ties have ceased to exist, and a gigantic and senseless dread [Angst] is set free. 
Roger Kaplan wrote;
- It matters little whether primary group cohesion acts as a "psychological prop" or as a performance motivator, because the net effect of reducing combat inhibitors (stress, fear, isolation) or promoting esprit, morale, and teamwork is the same - enhanced fighting power. 
Unit cohesion and "Don't Ask, Don't Tell"
Colonel Om Prakash, of the U.S. Air Force, wrote an essay, The Efficacy of “Don’t Ask, Don’t Tell”, which won first place in the Secretary of Defense Writing Contest for 2009. It was published in Joint Forces Quarterly, a publication of the U.S. National Defense University. 
Professor Robert MacCoun says that "... introduction of a homosexual man or woman into a work group could conceivably affect performance if he or she were ostracized from the group", nonetheless concluding that:
The presence of acknowledged homosexuals may reduce social cohesion in some units, but seems unlikely to undermine task cohesion. Research indicates that it is not necessary to like someone to work with them, so long as members share a commitment to the group's objectives.
- Slate, Dec. 1, 2010
- Geoff von Epps, "Relooking Unit Cohesion: A sensemaking approach", Military Review
- Cited by MediaMatters , quoting From foreign policy journal editor Mackubin Thomas Owens' February 3, 2010 Wall Street Journal op-ed
- Mackubin Owens (February 2000), "Military Ethos and the Politics of “Don’t Ask, Don’t Tell” On Principle", Ashbrook Center, Ashland University
- Om Prakash, "The Efficacy of “Don’t Ask, Don’t Tell”", Joint Forces Quarterly
- Gregory M. Herek, Unit Cohesion and the Military Mission, University of California at Davis