Editing Group dynamics (section)

===Group cohesion===
{{Main|Group cohesiveness}}
In the social sciences, group cohesion refers to the processes that keep members of a social group connected.<ref name=Dion/> Terms such as attraction, solidarity, and morale are often used to describe group cohesion.<ref name=Dion/> It is thought to be one of the most important characteristics of a group, and has been linked to group performance,<ref>{{Cite journal | last1 = Gully | first1 = S. M. | last2 = Devine | first2 = D. J. | last3 = Whitney | first3 = D. J. | doi = 10.1177/1046496495264003 | title = A Meta-Analysis of Cohesion and Performance: Effects of Level of Analysis and Task Interdependence | journal = Small Group Research | volume = 26 | issue = 4 | pages = 497–520 | year = 1995 | s2cid = 145303557 }}</ref> [[group conflict|intergroup conflict]]<ref>{{Cite journal | last1 = Stein | first1 = A. A. | doi = 10.1177/002200277602000106 | title = Conflict and Cohesion: A Review of the Literature | journal = Journal of Conflict Resolution | volume = 20 | pages = 143–172 | year = 1976 | s2cid = 145093926 }}</ref> and therapeutic change.<ref>{{cite book | last = Yalom | first = Irvin | title = The theory and practice of group psychotherapy | publisher = Basic Books | location = New York | year = 1995 | isbn = 978-0-465-08448-7 | url-access = registration | url = https://archive.org/details/theorypracticeo00yalo }}</ref>

Group cohesion, as a scientifically studied property of groups, is commonly associated with Kurt Lewin and his student, [[Leon Festinger]]. Lewin defined group cohesion as the willingness of individuals to stick together, and believed that without cohesiveness a group could not exist.<ref name=Dion/> As an extension of Lewin's work, Festinger (along with [[Stanley Schachter]] and Kurt Back) described cohesion as, “the total field of forces which act on members to remain in the group” (Festinger, Schachter, & Back, 1950, p.&nbsp;37).<ref name=Dion/> Later, this definition was modified to describe the forces acting on individual members to remain in the group, termed ''attraction to the group''.<ref name=Dion/> Since then, several models for understanding the concept of group cohesion have been developed, including Albert Carron's hierarchical model<ref>{{Cite journal | last1 = Carron | first1 = A. V. | last2 = Brawley | first2 = L. R. | doi = 10.1177/104649640003100105 | title = Cohesion: Conceptual and Measurement Issues | journal = Small Group Research | volume = 31 | pages = 89–106 | year = 2000 | s2cid = 220367599 }}</ref> and several bi-dimensional models (vertical v. horizontal cohesion, task v. social cohesion, belongingness and morale, and personal v. social attraction). Before Lewin and Festinger, there were, of course, descriptions of a very similar group property. For example, [[Emile Durkheim]] described two forms of solidarity (mechanical and organic), which created a sense of collective conscious and an emotion-based sense of community.<ref>{{cite book | last = Driedger | first = Leo | title = Multi-ethnic Canada : identities and inequalities | publisher = Oxford University Press | location = Toronto New York | year = 1996 | isbn = 978-0-19-541161-4 }}</ref>