Group cohesiveness, also called group cohesion or social cohesion, arises when bonds link members of a social group to one another and to the group as a whole. Although cohesion is a multi-faceted process, it can be broken down into four main components: social relations, task relations, perceived unity, and emotions. Members of strongly cohesive groups are more inclined to participate readily and to stay with the group.
From Neo-Latin cohaesio and French cohésion, in physics, cohesion means "the force that unites the molecules of a liquid or of a solid". Thereby, there are different ways to define group cohesion, depending on how researchers conceptualize this concept. However, most researchers define cohesion to be task commitment and interpersonal attraction to the group.
Cohesion can be more specifically defined as the tendency for a group to be in unity while working towards a goal or to satisfy the emotional needs of its members. This definition includes important aspects of cohesiveness, including its multidimensionality, dynamic nature, instrumental basis, and emotional dimension. Its multidimensionality refers to how cohesion is based on many factors. Its dynamic nature refers to how it gradually changes over time in its strength and form from the time a group is formed to when a group is disbanded. Its instrumental basis refers to how people cohere for some purpose, whether it be for a task or for social reasons. Its emotional dimension refers to how cohesion is pleasing to its group members. This definition can be generalized to most groups characterized by the group definition discussed above. These groups include sports teams, work groups, military units, fraternity groups, and social groups. However, it is important to note that other researchers claim that cohesion cannot be generalized across many groups.
The bonds between group members do not develop spontaneously. They develop from a number of components such as attraction, coordination, sense of belonging and shared emotions.