Group dynamics is a system of behaviors and psychological processes occurring within a social group (intragroup dynamics), or between social groups (intergroup dynamics). The study of group dynamics can be useful in understanding decision-making behavior, tracking the spread of diseases in society, creating effective therapy techniques, and following the emergence and popularity of new ideas and technologies. Group dynamics are at the core of understanding racism, sexism, and other forms of social prejudice and discrimination. These applications of the field are studied in psychology, sociology, anthropology, political science, epidemiology, education, social work, business, and communication studies.
- 1 History
- 2 Key theorists
- 3 Intragroup dynamics
- 4 Intergroup dynamics
- 5 Selected academic journals
- 6 See also
- 7 References
The history of group dynamics (or group processes) has a consistent, underlying premise: 'the whole is greater than the sum of its parts.' A social group is an entity, which has qualities that cannot be understood just by studying the individuals that make up the group. In 1924, Gestalt psychologist, Max Wertheimer identified this fact, stating ‘There are entities where the behavior of the whole cannot be derived from its individual elements nor from the way these elements fit together; rather the opposite is true: the properties of any of the parts are determined by the intrinsic structural laws of the whole’ (Wertheimer 1924, p. 7).
As a field of study, group dynamics has roots in both psychology and sociology. Wilhelm Wundt (1832–1920), credited as the founder of experimental psychology, had a particular interest in the psychology of communities, which he believed possessed phenomena (human language, customs, and religion) that could not be described through a study of the individual. On the sociological side, Émile Durkheim (1858–1917), who was influenced by Wundt, also recognized collective phenomena, such as public knowledge. Other key theorists include Gustave Le Bon (1841–1931) who believed that crowds possessed a 'racial unconscious' with primitive, aggressive, and antisocial instincts, and William McDougall (psychologist), who believed in a 'group mind,' which had a distinct existence born from the interaction of individuals.
Ultimately, it was social psychologist Kurt Lewin (1890–1947) who coined the term group dynamics to describe the positive and negative forces within groups of people. In 1945, he established The Group Dynamics Research Center at the Massachusetts Institute of Technology, the first institute devoted explicitly to the study of group dynamics. Throughout his career, Lewin was focused on how the study of group dynamics could be applied to real-world, social issues.
An increasing amount of research has applied evolutionary psychology principles to group dynamics. Humans are argued to have evolved in an increasingly complicated social environment and to have many adaptations concerned with group dynamics. Examples include mechanisms for dealing with status, reciprocity, identifying cheaters, ostracism, altruism, group decision, leadership, and intergroup relations.
Gustave Le Bon
Gustave Le Bon was a French social psychologist whose seminal study, The Crowd: A Study of the Popular Mind (1896) led to the development of group psychology.
The British psychologist William McDougall in his work The Group Mind (1920) researched the dynamics of groups of various sizes and degrees of organization.
In Group Psychology and the Analysis of the Ego, (1922), Sigmund Freud based his preliminary description of group psychology on Le Bon's work, but went on to develop his own, original theory, related to what he had begun to elaborate in Totem and Taboo. Theodor Adorno reprised Freud's essay in 1951 with his Freudian Theory and the Pattern of Fascist Propaganda, and said that "It is not an overstatement if we say that Freud, though he was hardly interested in the political phase of the problem, clearly foresaw the rise and nature of fascist mass movements in purely psychological categories."
Jacob L. Moreno
Jacob L. Moreno was a psychiatrist, dramatist, philosopher and theoretician who coined the term "group psychotherapy" in the early 1930s and was highly influential at the time.
Kurt Lewin (1943, 1948, 1951) is commonly identified as the founder of the movement to study groups scientifically. He coined the term group dynamics to describe the way groups and individuals act and react to changing circumstances. Group dynamics can be defined as a field of enquiry dedicated to the advancing knowledge about the nature of groups, the laws of their development and their interrelations with individuals, other groups and larger institutions. Based on their feelings and emotions, members of a group form a common perception. The interactive psychological relationship in which members of a group form this common perception is actually "Group Dynamics".
The phrase "Group Dynamics" contains two words- (i) Group- a social unit of two or more individuals who have in common a set of beliefs and values, follow the same norms and work for an establishable common aim. The members of the group share a set of common purpose, tasks or goals. (ii) Dynamics- the flow of, coherent activities which as envisaged, will lead the group towards the establishment of its set goals.
William Schutz (1958, 1966) looked at interpersonal relations from the perspective of three dimensions: inclusion, control, and affection. This became the basis for a theory of group behavior that sees groups as resolving issues in each of these stages in order to be able to develop to the next stage. Conversely, a group may also devolve to an earlier stage if unable to resolve outstanding issues in a particular stage. He referred to these group dynamics as "the interpersonal underworld" because they dealt with group processes that were largely unseen, as opposed to "content" issues, which were nominally the agenda of group meetings.
Wilfred Bion (1961) studied group dynamics from a psychoanalytic perspective, and stated that he was much influenced by Wilfred Trotter for whom he worked at University College Hospital London, as did another key figure in the Psychoanalytic movement, Ernest Jones. He discovered several mass group processes which involved the group as a whole adopting an orientation which, in his opinion, interfered with the ability of a group to accomplish the work it was nominally engaged in. His experiences are reported in his published books, especially Experiences in Groups. The Tavistock Institute has further developed and applied the theory and practices developed by Bion.
Bruce Tuckman (1965) proposed the four-stage model called Tuckman's Stages for a group. Tuckman's model states that the ideal group decision-making process should occur in four stages:
- Forming (pretending to get on or get along with others)
- Storming (letting down the politeness barrier and trying to get down to the issues even if tempers flare up)
- Norming (getting used to each other and developing trust and productivity)
- Performing (working in a group to a common goal on a highly efficient and cooperative basis)
Tuckman later added a fifth stage for the dissolution of a group called adjourning. (Adjourning may also be referred to as mourning, i.e. mourning the adjournment of the group). This model refers to the overall pattern of the group, but of course individuals within a group work in different ways. If distrust persists, a group may never even get to the norming stage.
M. Scott Peck
M. Scott Peck developed stages for larger-scale groups (i.e., communities) which are similar to Tuckman's stages of group development. Peck describes the stages of a community as:
- True Community
Communities may be distinguished from other types of groups, in Peck's view, by the need for members to eliminate barriers to communication in order to be able to form true community. Examples of common barriers are: expectations and preconceptions; prejudices; ideology, counterproductive norms, theology and solutions; the need to heal, convert, fix or solve and the need to control. A community is born when its members reach a stage of "emptiness" or peace.
Richard Hackman developed a synthetic, research-based model for designing and managing work groups. Hackman suggested that groups are successful when they satisfy internal and external clients, develop capabilities to perform in the future, and when members find meaning and satisfaction in the group. Hackman proposed five conditions that increase the chance that groups will be successful. These include:
- Being a real team: which results from having a shared task, clear boundaries which clarify who is inside or outside of the group, and stability in group membership.
- Compelling direction: which results from a clear, challenging, and consequential goal.
- Enabling structure: which results from having tasks which have variety, a group size that is not too large, talented group members who have at least moderate social skill, and strong norms that specify appropriate behavior.
- Supportive context: that occurs in groups nested in larger groups (e.g. companies). In companies, supportive contexts involves a) reward systems that reward performance and cooperation (e.g. group based rewards linked to group performance), b) an educational system that develops member skills, c) an information and materials system that provides the needed information and raw materials (e.g. computers).
- Expert coaching: which occurs on the rare occasions when group members feels they need help with task or interpersonal issues. Hackman emphasizes that many team leaders are overbearing and undermine group effectiveness.
Intragroup dynamics (also referred to as ingroup-, within-group, or commonly just ‘group dynamics’) are the underlying processes that give rise to a set of norms, roles, relations, and common goals that characterize a particular social group. Examples of groups include religious, political, military, and environmental groups, sports teams, work groups, and therapy groups. Amongst the members of a group, there is a state of interdependence, through which the behaviors, attitudes, opinions, and experiences of each member are collectively influenced by the other group members. In many fields of research, there is an interest in understanding how group dynamics influence individual behavior, attitudes, and opinions.
The dynamics of a particular group depend on how one defines the boundaries of the group. Often, there are distinct subgroups within a more broadly defined group. For example, one could define U.S. residents (‘Americans’) as a group, but could also define a more specific set of U.S. residents (for example, 'Americans in the South'). For each of these groups, there are distinct dynamics that can be discussed. Notably, on this very broad level, the study of group dynamics is similar to the study of culture. For example, there are group dynamics in the U.S. South that sustain a culture of honor, which is associated with norms of toughness, honor-related violence, and self-defense.
Group formation starts with a psychological bond between individuals. The social cohesion approach suggests that group formation comes out of bonds of interpersonal attraction. In contrast, the social identity approach suggests that a group starts when a collection of individuals perceive that they share some social category (‘smokers’, ‘nurses,’ ‘students,’ ‘hockey players’), and that interpersonal attraction only secondarily enhances the connection between individuals. Additionally, from the social identity approach, group formation involves both identifying with some individuals and explicitly not identifying with others. So to say, a level of psychological distinctiveness is necessary for group formation. Through interaction, individuals begin to develop group norms, roles, and attitudes which define the group, and are internalized to influence behavior.
Emergent groups arise from a relatively spontaneous process of group formation. For example, in response to a natural disaster, an emergent response group may form. These groups are characterized as having no preexisting structure (e.g. group membership, allocated roles) or prior experience working together. Yet, these groups still express high levels of interdependence and coordinate knowledge, resources, and tasks.
The social group is a critical source of information about individual identity. An individual’s identity (or self-concept) has two components: personal identity and social identity (or collective self). One’s personal identity is defined by more idiosyncratic, individual qualities and attributes. In contrast, one’s social identity is defined by his or her group membership, and the general characteristics (or prototypes) that define the group and differentiate it from others. We naturally make comparisons between our own group and other groups, but we do not necessarily make objective comparisons. Instead, we make evaluations that are self-enhancing, emphasizing the positive qualities of our own group (see ingroup bias). In this way, these comparisons give us a distinct and valued social identity that benefits our self-esteem. Our social identity and group membership also satisfies a need to belong. Of course, individuals belong to multiple groups. Therefore, one’s social identity can have several, qualitatively distinct parts (for example, one’s ethnic identity, religious identity, and political identity).
Optimal distinctiveness theory suggests that individuals have a desire to be similar to others, but also a desire to differentiate themselves, ultimately seeking some balance of these two desires (to obtain optimal distinctiveness). For example, one might imagine a young teenager in the United States who tries to balance these desires, not wanting to be ‘just like everyone else,’ but also wanting to ‘fit in’ and be similar to others. One’s collective self may offer a balance between these two desires. That is, to be similar to others (those who you share group membership with), but also to be different from others (those who are outside of your group).
In the social sciences, group cohesion refers to the processes that keep members of a social group connected. Terms such as attraction, solidarity, and morale are often used to describe group cohesion. It is thought to be one of the most important characteristics of a group, and has been linked to group performance, intergroup conflict and therapeutic change.
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. 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. 37). Later, this definition was modified to describe the forces acting on individual members to remain in the group, termed attraction to the group. Since then, several models for understanding the concept of group cohesion have been developed, including Albert Carron’s hierarchical model 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.
Black sheep effect
Beliefs within the ingroup are based on how individuals in the group see their other members. Individuals tend to upgrade likeable in-group members and deviate from unlikeable group members, making them a separate outgroup. This is called the black sheep effect. A person's beliefs about the group may be changed depending upon whether they are part of the ingroup or outgroup.
New members of a group must prove themselves to the full members, or “old-timers”, to become accepted. Full members have undergone socialization and are already accepted within the group. They have more privilege than newcomers but more responsibility to help the group achieve its goals. Marginal members were once full members but lost membership because they failed to live up to the group’s expectations. They can rejoin the group if they go through re-socialization. In a Bogart and Ryan study, the development of new members' stereotypes about in-groups and out-groups during socialization was surveyed. Results showed that the new members judged themselves as consistent with the stereotypes of their in-groups, even when they had recently committed to join those groups or existed as marginal members. They also tended to judge the group as a whole in an increasingly less positive manner after they became full members.
Depending on the self-esteem of an individual, members of the in-group may experience different private beliefs about the group’s activities but will publicly express the opposite—that they actually share these beliefs. One member may not personally agree with something the group does, but to avoid the black sheep effect, they will publicly agree with the group and keep the private beliefs to themselves. If the person is privately self-aware, he or she is more likely to comply with the group even if they possibly have their own beliefs about the situation.
In situations of hazing within fraternities and sororities on college campuses, pledges may encounter this type of situation and may outwardly comply with the tasks they are forced to do regardless of their personal feelings about the Greek institution they are joining. This is done in an effort to avoid becoming an outcast of the group. Outcasts who behave in a way that might jeopardize the group tend to be treated more harshly than the likeable ones in a group, creating a black sheep effect. Full members of a fraternity might treat the incoming new members harshly, causing the pledges to decide if they approve of the situation and if they will voice their disagreeing opinions about it.
Group influence on individual behavior
Individual behavior is influenced by the presence of others. For example, studies have found that individuals work harder and faster when others are present (see social facilitation), and that an individual’s performance is reduced when others in the situation create distraction or conflict. Groups also influence individual’s decision-making processes. These include decisions related to ingroup bias, persuasion (see Asch conformity experiments), obedience (see Milgram Experiment), and groupthink. There are both positive and negative implications of group influence on individual behavior. This type of influence is often useful in the context of work settings, team sports, and political activism. However, the influence of groups on the individual can also generate extremely negative behaviors, evident in Nazi Germany, the My Lai Massacre, and in the Abu Ghraib prison (also see Abu Ghraib torture and prisoner abuse).
A group's structure is the internal framework that defines members' relations to one another over time. Frequently studied elements of group structure include roles, norms, values, communication patterns, and status differentials.
Roles can be defined as a tendency to behave, contribute and interrelate with others in a particular way. Roles may be assigned formally, but more often are defined through the process of role differentiation. Role differentiation is the degree to which different group members have specialized functions. Functional (task) roles are generally defined in relation to the tasks the team is expected to perform. Other types of roles are the socio-emotional role, which helps maintain the social fabric of the group, the individual role and the leader role.
Norms are the informal rules that groups adopt to regulate members' behaviour. Norms refer to what should be done and represent value judgments about appropriate behaviour in social situations. Although they are infrequently written down or even discussed, norms have powerful influence on group behaviour.
Values are goals or ideas that serve as guiding principles for the group. Like norms, values may be communicated either explicitly or on an ad hoc basis. Values can serve as a rallying point for the team. However, some values (such as conformity) can also be dysfunction and lead to poor decisions by the team.
Communication patterns describe the flow of information within the group and they are typically described as either centralized or decentralized. With a centralized pattern, communications tend to flow from one source to all group members. Centralized communications allow consistent, standardization information but they may restrict the free flow of information. Decentralized communications make it easy to share information directly between group members. When decentralized, communications tend to flow more freely, but the delivery of information may not be as fast or accurate as with centralized communications. Another potential downside of decentralized communications is the sheer volume of information that can be generated, particularly with electronic media.
Status differentials are the relative differences in status among group members. Status can be determined by a variety of factors, including expertise, occupation, age, gender or ethnic origin. Status differentials may affect the relative amount of pay among group members and they may also affect the group's tolerance to violation of group norms (i.e., people with higher status are given more freedom to violate group norms).
Intergroup dynamics refers to the behavioral and psychological relationship between two or more groups. This includes perceptions, attitudes, opinions, and behaviors towards one’s own group, as well as those towards another group. In some cases, intergroup dynamics is prosocial, positive, and beneficial (for example, when multiple research teams work together to accomplish a task or goal). In other cases, intergroup dynamics can create conflict. For example, Fischer & Ferlie found initially positive dynamics between a clinical institution and its external authorities dramatically changed to a 'hot' and intractable conflict when authorities interfered with its embedded clinical model. Similarly, underlying the 1999 Columbine High School shooting in Littleton, Colorado, United States, intergroup dynamics played a significant role in Eric Harris’ and Dylan Klebold’s decision to kill a teacher and 14 students (including themselves).
According to social identity theory, intergroup conflict starts with a process of comparison between individuals in one group (the ingroup) to those of another group (the outgroup). This comparison process is not unbiased and objective. Instead, it is a mechanism for enhancing one’s self-esteem. In the process of such comparisons, an individual tends to:
- favor the ingroup over the outgroup
- exaggerate and overgeneralize the differences between the ingroup and the outgroup (to enhance group distinctiveness)
- minimize the perception of differences between ingroup members
- remember more detailed and positive information about the ingroup, and more negative information about the outgroup
Even without any intergroup interaction (as in the minimal group paradigm), individuals begin to show favoritism towards their own group, and negative reactions towards the outgroup. This conflict can result in prejudice, stereotypes, and discrimination. Intergroup conflict can be highly competitive, especially for social groups with a long history of conflict (for example, the 1994 Rwandan Genocide, rooted in group conflict between the ethnic Hutu and Tutsi). In contrast, intergroup competition can sometimes be relatively harmless, particularly in situations where there is little history of conflict (for example, between students of different universities) leading to relatively harmless generalizations and mild competitive behaviors. Intergroup conflict is commonly recognized amidst racial, ethnic, religious, and political groups.
The formation of intergroup conflict was investigated in a popular series of studies by Muzafer Sherif and colleagues in 1961, called the Robbers Cave Experiment. The Robbers Cave Experiment was later used to support realistic conflict theory. Other prominent theories relating to intergroup conflict include social dominance theory, and social-/self-categorization theory.
Intergroup conflict reduction
There have been several strategies developed for reducing the tension, bias, prejudice, and conflict between social groups. These include the contact hypothesis, the jigsaw classroom, and several categorization-based strategies.
Contact hypothesis (intergroup contact theory)
In 1954, Gordon Allport suggested that by promoting contact between groups, prejudice can be reduced. Further, he suggested four optimal conditions for contact: equal status between the groups in the situation; common goals; intergroup cooperation; and the support of authorities, law, or customs. Since then, over 500 studies have been done on prejudice reduction under variations of the contact hypothesis, and a meta-analytic review suggests overall support for its efficacy. In some cases, even without the four optimal conditions outlined by Allport, prejudice between groups can be reduced.
Under the contact hypothesis, several models have been developed. A number of these models utilize a superordinate identity to reduce prejudice. That is, a more broadly defined, ‘umbrella’ group/identity that includes the groups that are in conflict. By emphasizing this superordinate identity, individuals in both subgroups can share a common social identity. For example, if there is conflict between White, Black, and Latino students in a high school, one might try to emphasize the ‘high school’ group/identity that students share to reduce conflict between the groups. Models utilizing superordinate identities include the common ingroup identity model, the ingroup projection model, the mutual intergroup differentiation model, and the ingroup identity model.
There are also techniques for reducing prejudice that utilize interdependence between two or more groups. That is, members across groups have to rely on one another to accomplish some goal or task. In the Robbers Cave Experiment, Sherif used this strategy to reduce conflict between groups. Elliot Aronson’s Jigsaw Classroom also uses this strategy of interdependence. In 1971, thick racial tensions were abounding in Austin, Texas. Aronson was brought in to examine the nature of this tension within schools, and to devise a strategy for reducing it (so to improve the process of school integration, mandated under Brown v. Board of Education in 1954). Despite strong evidence for the effectiveness of the jigsaw classroom, the strategy was not widely used (arguably because of strong attitudes existing outside of the schools, which still resisted the notion that racial and ethnic minority groups are equal to Whites and, similarly, should be integrated into schools).
Selected academic journals
- Group Processes & Intergroup Relations
- Group Dynamics: Theory, Research, and Practice
- Small Group Research
- Group Analysis
- International Journal of Group Psychotherapy
- The Journal for Specialists in Group Work
- Social Work With Groups
- International Journal on Minority and Group Rights
- Group Facilitation: A Research and Applications Journal
- Backstrom, L.; Huttenlocher, D.; Kleinberg, J.; Lan, X. (2006). "Group formation in large social networks". Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining - KDD '06. p. 44. doi:10.1145/1150402.1150412. ISBN 1595933395.
- Hogg, M. A.; Williams, K. D. (2000). "From I to we: Social identity and the collective self". Group Dynamics: Theory, Research, and Practice 4: 81. doi:10.1037/1089-26184.108.40.206.
- Westheimer, G. (1999). "Gestalt theory reconfigured: Max Wertheimer's anticipation of recent developments in visual neuroscience". Perception 28 (1): 5–15. doi:10.1068/p2883. PMID 10627849.
- Dion, K. L. (2000). "Group cohesion: From "field of forces" to multidimensional construct". Group Dynamics: Theory, Research, and Practice 4: 7–2. doi:10.1037//1089-26220.127.116.11.
- gupta, niranjan (2013). "The Research Center for tcce pindra garhwa". Sociometry 8 (2): 126–136. doi:10.2307/2785233. JSTOR 2785233.
- Van Vugt, M.; Schaller, M. (2008). "Evolutionary approaches to group dynamics: An introduction". Group Dynamics: Theory, Research, and Practice 12: 1. doi:10.1037/1089-2618.104.22.168.
- Hammer, Espen Adorno and the political, pp.58-9
- Schutz, W. (1958). FIRO: A Three-Dimensional Theory of Interpersonal Behavior. New York, NY: Rinehart.
- Schutz, W. (1966). The Interpersonal Underworld. (Updated version based on 1958 work). Palo Alto, CA: Science and Behavior Books.
- Page 194 to 196, Irvin D. Yalom, The Theory and Practice of Group Psychotherapy, third edition, Basic Books (1985), hardback, ISBN 0-465-08447-8
- Peck, M. S. (1987) The Different Drum: Community-Making and Peace.p. 95-103.
- J. Richard Hackman (2002). Leading Teams: Setting the Stage for Great Performances. Harvard Business Press.
- Wageman, R. (1995). "Interdependence and Group Effectiveness". Administrative Science Quarterly 40 (1): 145–180. doi:10.2307/2393703.
- Cohen, D.; Nisbett, R. E.; Bowdle, B. F.; Schwarz, N. (1996). "Insult, aggression, and the southern culture of honor: An "experimental ethnography."". Journal of Personality and Social Psychology 70 (5): 945–959. doi:10.1037/0022-3522.214.171.1245. PMID 8656339.
- Cohen, D. (1998). "Culture, social organization, and patterns of violence". Journal of Personality and Social Psychology 75 (2): 408–419. doi:10.1037/0022-35126.96.36.1998. PMID 9731316.
- Sherif, M. (1936). The psychology of social norms. New York: Harper.
- Majchrzak, A.; Jarvenpaa, S. L.; Hollingshead, A. B. (2007). "Coordinating Expertise Among Emergent Groups Responding to Disasters". Organization Science 18: 147. doi:10.1287/orsc.1060.0228.
- Crano, W. D. (2000). "Milestones in the psychological analysis of social influence". Group Dynamics: Theory, Research, and Practice 4: 68–61. doi:10.1037/1089-26188.8.131.52.
- Spears, R.; Ellemers, N.; Doosje, B. (2005). "Let me count the ways in which I respect thee: Does competence compensate or compromise lack of liking from the group?". European Journal of Social Psychology 35 (2): 263. doi:10.1002/ejsp.248.
- Deaux, K.; Reid, A.; Mizrahi, K.; Ethier, K. A. (1995). "Parameters of social identity". Journal of Personality and Social Psychology 68 (2): 280. doi:10.1037/0022-35184.108.40.2060.
- Brewer, M. B. (1991). "The Social Self: On Being the Same and Different at the Same Time". Personality and Social Psychology Bulletin 17 (5): 475. doi:10.1177/0146167291175001.
- Gully, S. M.; Devine, D. J.; Whitney, D. J. (1995). "A Meta-Analysis of Cohesion and Performance: Effects of Level of Analysis and Task Interdependence". Small Group Research 26 (4): 497. doi:10.1177/1046496495264003.
- Stein, A. A. (1976). "Conflict and Cohesion: A Review of the Literature". Journal of Conflict Resolution 20: 143. doi:10.1177/002200277602000106.
- Yalom, Irvin (1995). The theory and practice of group psychotherapy. New York: Basic Books. ISBN 978-0-465-08448-7.
- Carron, A. V.; Brawley, L. R. (2000). "Cohesion: Conceptual and Measurement Issues". Small Group Research 31: 89. doi:10.1177/104649640003100105.
- Driedger, Leo (1996). Multi-ethnic Canada : identities and inequalities. Toronto New York: Oxford University Press. ISBN 0-19-541161-7.
- Pinto, I. R., Marques, J. M. & Abrams D. (2010). Membership status and subjective group dynamics: Who triggers the black sheep effect? Journal of Personality and Social Psychology. 99 (1), 107-119
- Ryan, Carey S.; Bogart, Laura M. (Oct 1997). "Development of new group members' in-group and out-group stereotypes: Changes in perceived variability and ethnocentrism". Journal of Personality and Social Psychology 73 (4): 719–732. doi:10.1037/0022-35220.127.116.119.
- Aronson, Elliot (2008). The social animal. New York: Worth Publishers. ISBN 1-4292-0316-1.
- Wittenbaum and Moreland. (2008). Small-Group Research in Social Psychology: Topics and Trends over Time.
- Jex, Steve &; Britt, Thomas (2008). Organizational Psychology: A Scientist-Practitioner Approach (Second ed.). Hoboken, New Jersey: John Wiley & Sons, Inc. pp. 341–365.
- Levine. (1998). The Handbook of Social Psychology.
- Senior. (1991). Journal of Occupational and Organizational Psychology.
- Hahn, M. (2010). Group Norms in Organizations.
- Schwarz. (2007). Are There Universal Aspects in the Structure and Contents of Human Values?
- Fischer, Michael Daniel; Ferlie, Ewan (1 January 2013). "Resisting hybridisation between modes of clinical risk management: Contradiction, contest, and the production of intractable conflict". Accounting, Organizations and Society 38 (1): 30–49. doi:10.1016/j.aos.2012.11.002.
- Turner, J. C. (1975). "Social comparison and social identity: Some prospects for intergroup behaviour". European Journal of Social Psychology 5: 1. doi:10.1002/ejsp.2420050102.
- Gaertner, S. L.; Dovidio, J. F.; Banker, B. S.; Houlette, M.; Johnson, K. M.; McGlynn, E. A. (2000). "Reducing intergroup conflict: From superordinate goals to decategorization, recategorization, and mutual differentiation". Group Dynamics: Theory, Research, and Practice 4: 98. doi:10.1037/1089-2618.104.22.168.
- Sherif, Muzafer (1988). The Robbers Cave Experiment. Middletown: Wesleyan University Press. ISBN 0-8195-6194-0.
- Levine, Robert (1971). Ethnocentrism: Theories of Conflict, Ethnic Attitudes, and Group Behavior. New York: Wiley. ISBN 0-471-53117-0.
- Allport, Gordon (1979). The Nature of Prejudice. Reading: Addison-Wesley Pub. Co. ISBN 0-201-00179-9.
- Pettigrew, T. F.; Tropp, L. R. (2006). "A Meta-Analytic Test of Intergroup Contact Theory". Journal of Personality and Social Psychology 90 (5): 751–783. doi:10.1037/0022-3522.214.171.1241. PMID 16737372.
- Hornsey, M. J.; Hogg, M. A. (2000). "Subgroup Relations: A Comparison of Mutual Intergroup Differentiation and Common Ingroup Identity Models of Prejudice Reduction". Personality and Social Psychology Bulletin 26 (2): 242. doi:10.1177/0146167200264010.
- Aronson, Elliot (1997). The Jigsaw Classroom. New York: Longman. ISBN 978-0-673-99383-0.