Group cohesion is a phenomenon that determines how well a group holds together. When cohesion is strong, a group will remain stable, but when it is weak, the group may fall apart. The study of group cohesion is a topic of interest among social psychologists and many others, including people who are concerned with making large organizations work effectively. Understanding this phenomenon can be key to pulling together a team, a workplace, or a similar group of people.
Some of the factors in how a group holds together are social. There are a number of things that can occur within a group and its members that encourage people to stay in the group and to stay focused on group goals. Others are environmental, caused by external factors that make staying together as a group more or less appealing.
In many cases, the smaller a group is, the better the cohesion. The more stable a group is in terms of member demographics, the better the cohesion as well. People who share characteristics like gender, race, sex, religion, and so forth will typically forge stronger connections in a group, while a group of diverse individuals may have difficulty staying together. Another factor is group success, with people having an incentive to stay in a group that is doing well, with elitism also playing a role.
The famous quote attributed to several different people goes “I would not join any club that would have someone like me as a member.” This holds true for group cohesion as well; the harder it is to get in to a group, the more incentive people have to stay. In a simple example, students at an elite university experience a form of cohesion because they share many characteristics, including admission into an elite educational institution. Task cohesion is another factor; if a group has a task to focus on which requires collective effort, it will have an easier time staying together. A famous example of this is a military mission.
There may also be rewards and punishments involved. People could be rewarded for being in a group with benefits that make the group attractive to be in, or they could face punishment for leaving the group, which encourages them to stay. The key external factor, on the other hand, is competition from other groups. A swim team may fall apart if it never has any meets, but as soon as a rival team appears, group cohesion will often increase radically, because members have an incentive to stay in the group and to work together to achieve a common goal: the defeat of the rival.