Group Dynamics:
Theory, Research, and Practice
© 2021 American Psychological Association
ISSN: 1089-2699
2021, Vol. 25, No. 3, 213–228
https://doi.org/10.1037/gdn0000163
Recent Advances in the Study of Group Cohesion
Donelson R. Forsyth
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Jepson School of Leadership Studies, University of Richmond
Objective: Group cohesion, as a central explanatory concept in the study of groups, has
provided a foundation for explaining a number of group processes that have occupied
researchers’ attention since the founding of the journal Group Dynamics: Theory,
Research, and Practice 25 years ago. Method: This review summarizes that research,
focusing on three specific topics: group performance, the effectiveness of group
psychotherapy, and group-based identity processes. Results: Theory and research in
these areas have yielded substantial insights into cohesion and related group processes,
but definitional, methodological, and theoretical uncertainties remain to be resolved.
Conclusions: Seeking to resolve some of these uncertainties, an integrative model of
cohesion that defines cohesion as a group’s degree of unity—and distinguishes between
the causes (or antecedents) of that unity (such as attraction bonds or group pride) and
indicators of cohesion—is described, as is a short inventory that can be used to assess
members’ perceptions of the unity of their groups.
Highlights and Implications
• The concept of cohesion is central to understanding groups and group
processes, and recent research has yielded substantial advances in understanding the
nature, the sources, and the consequences of this key group-level process.
• Specifically, recent research provides a clearer understanding of when
cohesion facilitates team performance, cohesion’s influence on the outcome of group
psychotherapy, and the relationship between cohesion and members’ social identities.
• To resolve continuing issues of definition and assessment, an integrative
conceptualization of cohesion, unitary cohesion theory, is described; it defines
cohesion as the unity of a group, and so distinguishes between the causes of
cohesion, indicators of cohesion, and cohesion itself.
• Recommendations for future research include identifying and documenting the type of cohesion assessed in specific instruments and using methods
that are appropriate when studying a group-level process.
• A unitary cohesion index is described. This set of bipolar rating scales can
be used to directly assess members’ estimates of their group’s cohesion by separating
the defining conditions of cohesion from the potential causes of cohesion.
Keywords: group cohesion, team performance, group psychotherapy, social identity,
unitary cohesion index
Supplemental materials: https://doi.org/10.1037/gdn0000163.supp
Correspondence concerning this article should be
addressed to Donelson R. Forsyth, Jepson School
of Leadership Studies, University of Richmond,
Jepson Hall, 221 Richmond Way, Richmond,
VA 23173, United States. Email: dforsyth@
richmond.edu
This article was published Online First July 22, 2021.
Donelson R. Forsyth https://orcid.org/0000-0002-2388-2953
Thanks are extended to Georgio Tasca and Rachel Forsyth
for their support in the development of this review and
design of the survey.
213
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214
FORSYTH
In the continuing quest to understand groups
and their dynamics, some theoretical concepts
have prospered more than others. Cattell’s (1948)
theory of syntality—the “synaction” of a group
and its members—evoked little interest among
those who study group-level processes. Bogardus
(1954) suggested that each group has its own
unique personality—its groupality—but this concept remains unstudied. Zander (1971) offered a
compelling analysis of group desire, but some
40 years later few have used this construct to
explain group motivation and achievement.
Group cohesion, in contrast, continues to capture the interest of those who study groups and
those who rely on groups professionally. It
emerged in nearly all the early theoretical works
that first examined interpersonal processes in
collectives, including Cooley’s (1909) theory
of primary groups, Durkheim’s (1897/1951)
analysis of solidarity, McDougall’s (1908) idea
of a gregarious instinct, and even Freud’s (1922)
primal horde. But as Dion (2000) observed in his
historical analysis of the concept, it was Lewin
who secured cohesion’s central place in subsequent theoretical and empirical studies of groups.
He and his colleagues maintained that cohesion—
that “total field of forces which act on members to
remain in the group” (Festinger et al., 1950,
p. 164)—was the key to understanding any number of group-level processes, including social
influence, conformity, communication, and leadership. Since that early work theorists and researchers have continued to investigate this
aspect of groups; refining it, crafting new ways
to measure it, and testing hypotheses about its
causes and consequences.
The fruits of those theoretical and empirical
efforts have been artfully summarized in a number of narrative and meta-analytic reviews (e.g.,
Bottoni, 2018; Cota et al., 1995; Dion, 2000;
Friedkin, 2004; Marmarosh & Sproul, 2021).
The current review complements these prior
analyses by examining how cohesion has provided a foundation—sometimes unrecognized—
for explaining a number of group processes that
have occupied researchers’ attention since the
founding of the journal Group Dynamics: Theory, Research, and Practice some 25 years ago.
During this period the journal has featured theoretical and empirical analyses of an everwidening range of group phenomena, and
many have drawn on the concept of cohesion
to explain group performance, change-promoting
processes in therapeutic groups, and social identity. After briefly reviewing these advances, challenges and prospects are also enumerated, for the
study of cohesion—despite the many years of
research devoted to this topic—is still hampered
by definitional, measurement, and theoretical
uncertainties.
Group Cohesion: Recent Advances
Just as groups pass through stages in their development from newly formed collectives of individuals into unified groups (Tuckman, 1965), so the
study of group cohesion has progressed through a
series of stages, with some marked by more rapid
progress than others. Throughout the heyday of
group research in the 1950s and 60s, researchers
used the concept of cohesion to better understand
social influence and power, loyalty and commitment, conformity and compliance, and the acquaintance process (Cartwright, 1968). After a brief
decline in interest in the 1970s, as researchers grappled with “excess conceptual, methodological, and
perhaps ideological baggage” (McGrath, 1997,
p. 12) in group research, interest in cohesion surged
once again, with researchers refining their assessments of cohesion and using it to explain such topics
as group decision-making, influence, and social
network processes. By the end of the century and
into the next, the concept continued to drive new
insights into group dynamics, including studies of
collective efficacy (e.g., Paskevich et al., 1999),
groupdevelopment(e.g., Bakaliet al.,2010),group
creativity (e.g., Craig & Kelly, 1999), cooperation
(De Cremer & Leonardelli, 2003), collective reactions to trauma (Burlingame & Layne, 2001), identifiability (Douglas & McGarty, 2002), sacrifice
(Prapavessis & Carron, 1997), and leadership
(Rast et al., 2016). All of these emerging areas
of the study drew on the concept of cohesion to gain
empirical traction, but here we consider three that
consistently highlighted the theoretical importance
of this concept: Group performance, the effectiveness of group psychotherapy, and group-based
identity processes.
Cohesion and Group Productivity
In the last 25 years research examining
group performance—and team performance
in particular—has thrived. Much of that work
has been done by researchers who study groups
in business and organizational settings, for
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UNIFIED COHESION THEORY
teams—which are, of course, groups—are relied
on at ever-increasing rates for management, production, and the delivery of services (Devine,
2002). Sports and exercise researchers, too,
have increasingly considered group-level processes in their study of the factors that determine
success and failure in team competitions (Spink,
2021). In science and medicine, investigators have
addressed the factors that determine the success of
collaborative groups in the emerging field of team
science (Fiore et al., 2019).
These advances have identified a variety of
factors that influence group performance, but
when success depends on coordination, strong
relational bonds, and commitment to group-level
goals, a group’s cohesion matters. Seventy years
ago, Schachter et al. (1951) stated the cohesion–
performance hypothesis clearly: “The more
cohesive the group the greater should be
its productivity” (pp. 229–230). Subsequent
researchers have repeatedly examined this assumption, in laboratory and field studies, using crosssectional and longitudinal designs, with groups in all
kinds of contexts (sports teams, workgroups, expeditions, military squads, etc.) and with varying
measures of cohesion and production. Their conclusion: In most cases, cohesive groups will outperform less unified groups (Beal et al., 2003; Carron
et al., 2002; Casey-Campbell & Martens, 2009;
Castaño et al., 2013; Chiocchio & Essiembre,
2009; Evans & Dion, 1991; Gully et al., 1995;
Mullen & Copper, 1994; Oliver et al., 1999).
Castaño et al.’s (2013) meta-analytic review of
132 studies of over 6,000 groups, for example,
reported a small but stable correlation (.21–.25)
between cohesion and performance.
These meta-analytic studies, however, suggest
that the relationship waxes and wanes across group
types, contexts, and methods of measurement. The
cohesion–performance relationship tends to be
stronger in business teams than in sports teams
or military groups (Castaño et al., 2013), and when
researchers use group-level rather than individuallevel measures (Gully et al., 1995). The source of
the group’s cohesion may also matter. Mullen and
Copper (1994) concluded measures that assess a
group’s unified commitment to goal achievement
are better predictors of performance, whereas more
recent analyses find that the source of the group’s
cohesion is not a moderating factor (Beal et al.,
2003; Castaño et al., 2013).
Researchers have also continued to investigate the processes that mediate the relationship
215
between cohesion and performance. The cohesion–
performance relationship tends to strengthen in
groups working on tasks that require higher levels
of interdependency; thus, cohesion may act as a
social lubricant that minimizes process loss (Beal
et al., 2003). Evidence also suggests that increases
in cohesion enhance motivational levels and limit
levels of social loafing (Karau & Williams, 1997).
Moreover, the relationships among cohesion,
motivation, and performance are reflexive; cohesion enhances motivation which improves performance, but improvements in performance also
cause increases in cohesion and motivation
(Mullen & Copper, 1994).
Cohesion and Group Psychotherapy
Once viewed with uncertainty by the mental
health community, group approaches to treatment
have emerged in recent years as a highly effective
method for helping people enhance their psychological well-being (Rosendahl et al., 2021). The
methodological shortcomings of initial empirical
investigations of group-level treatments were
substantial—so much so that only guarded conclusions could be offered about efficacy—but in
the last 25 years researchers have repeatedly
demonstrated the effectiveness of group psychotherapies in methodologically rigorous studies. Meta-analytic reviews support the use of
group therapy for helping people deal with traumatic experiences, depression, thought and mood
disorders, social phobia, obsessive–compulsive
tendencies, bulimia nervosa, binge eating,
substance-related problems, trauma, and the psychological complexities of physical illnesses (e.g.,
Barkowski et al., 2016; Burlingame et al., 2003,
2020; Janis et al., 2021; McRoberts et al., 1998).
The effectiveness of group approaches to treatment is determined by a multitude of group- and
individual-level factors, including pretraining,
leader orientation and directiveness, and levels
of member-to-member interpersonal feedback.
But theorists and researchers have consistently
identified cohesion as a critical determinant of
treatment effectiveness (Burlingame et al., 2011,
2018; Kivlighan et al., 2020). Most models of
group treatment explicitly cite the importance of
cohesiveness, in some cases suggesting it is a
necessary condition for therapeutic success
(Marmarosh & Van Horn, 2010). For example,
Lorentzen et al. (2018) tracked the level of cohesion in 18 short- and long-term analytic therapy
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216
FORSYTH
groups using the Therapeutic Factors Inventory
(Lese & MacNair-Semands, 2000). In the shortterm, but not long-term, groups, cohesion was a
significant predictor of positive gains in adjustment. When Norton and Kazantzis (2016) assessed
changes in cohesion across cognitive-behavioral
treatments for anxiety they found that the relationship between cohesion and treatment gain was
initially nonsignificant (r = −0.06), but it became
clinically and statistically significant over time
(r = −0.23). Chapman and Kivlighan (2019)
also affirmed the strengthening of the relationship
between cohesion (at the client level) and treatment
efficacy; clients who considered the group to be
more cohesive relative to others in the group exhibited better outcomes over time.
Meta-analytic reviews provide further evidence of the therapeutic benefits of cohesion in
psychotherapy groups (e.g., Burlingame et al.,
2011, 2018). Of the 55 studies conducted between
1967 and 2015 reviewed by Burlingame et al.
(2018), 29 reported a statistically significant positive relationship between cohesion and treatment
outcome. The correlation across all studies of
+0.26 prompted them to conclude “there is sufficient evidence to consider cohesion as an
evidence-based relationship factor for groups
guided by interpersonal, psychodynamic,
cognitive-behavioral, supportive, and eclectic
orientations” (p. 391).
Moreover, just as increases in cohesion result
in a number of gains in a variety of group-level
processes in performance-focused teams, evidence also suggests that other therapeutically
positive group-level processes depend, at least
in part, on cohesion-building processes. As
Yalom and Leszcz (2005, p. 55) put it, “cohesion
is not only a potent therapeutic force in its own
right,” but “a precondition for other therapeutic
factors to functional optimally.” Cohesive groups
are more successful in retaining their members,
and so increases in cohesion are associated with
regular attendance at sessions and increased
engagement with the group and its goals in
later stages of the group’s development (Bakali
et al., 2010). As studies of psychological safety
in teams in organizational contexts suggest
(e.g., Edmondson & Lei, 2014), cohesive groups
tend to provide higher levels of both direct and
indirect support to their members (Wanless,
2016). Trust and exchange of feedback between
members are more substantial in cohesive
groups (Slone et al., 2015), as is social influence
(Forsyth, 2021). Groups led by therapists who
intentionally take steps to increase their group’s
levels of cohesion yield more therapeutic gains
than groups whose leaders do not elevate levels of
cohesion (Burlingame et al., 2018). In sum, cohesion likely augments all the therapeutic factors
identified by Yalom and Leszcz’s (2005) interpersonal model: Universality, installation of
hope, imparting information, corrective recapitulation of the primary family experience, vicarious learning, interpersonal learning, guidance,
self-disclosure, catharsis, altruism, and insight.
Cohesion and Identity
The third area of research that has surged in the
last 25 years pertains to the relationship between
individuals and their groups. Long a topic of interest
to group theorists—for example, Freud (1922)
suggested group members’ self-conceptions align
as they identify with one another and their group’s
leader, Cooley (1909) distinguished between
individuals’ self-consciousness (their personal,
private qualities) and their public consciousness
(the qualities common to their group), and
McDougall (1921/2012) described how individuals in groups come to share a collective identity or group mind—the analysis of the nature of
the relationship between individual members’
sense of self and their group-level identity has
been reinvigorated in recent years as researchers
have tested hypotheses derived from such theoretical frameworks as social categorization theory
(e.g., Turner, 1982), social identity theory (e.g.,
Tajfel & Turner, 1986), collective self-esteem
theory (Luhtanen & Crocker, 1992), optimal
distinctiveness theory (Brewer, 2012), and
group-level group identity theory (Ozeki,
2015). The rise in the number of publications
dealing with groups in recent years is due, in large
part, to an upswing in interest in group-based
identity processes.
These researches have not only examined the
relationship between identity and members’
well-being (e.g., Hoffmann et al., 2020; Inoue
et al., 2015), personal and collective self-esteem
(e.g., Marmarosh & Corazzini, 1997), and the
stability of their self-concepts (Slotter et al.,
2015), but they have also clarified the relationship
between group identification and cohesion.
Prentice et al. (1994), for example, distinguish
between common-identity and common-bond
groups. In common-identity groups, members
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UNIFIED COHESION THEORY
are united by their commitment to the group itself,
whereas common-bond groups are “based primarily on attachments among group members”
(p. 485). In consequence, in their research they
found that in common-identity groups members
expressed a closer relationship to the group itself
rather than the individuals. In contrast, in
common-bond groups members’ liking for and
evaluation of specific members was the better
predictor of attachment to the group (cohesion) in
general. Extending their findings, Sassenberg
(2002) found that (a) conformity to norms that
guided communication in online groups was
more pronounced in common-identity groups,
in comparison to common-bond groups but that
(b) members who strongly identified with their
group were less likely to conform to a norm that
would potentially harm the group (Täuber &
Sassenberg, 2012).
The substantial connection between cohesion
and members’ shared identification with their
groups is also consistent with social identity
theory (e.g., Hogg, 1992, 2001). That theory
suggests that although members of cohesive
groups usually like one another, this personal
attraction is not group cohesion. Rather, cohesion
is determined by social categorization and identification processes. Members of cohesive groups
recognize that they are members of the group—
their membership in the group is salient to them
(categorization)—and their social identities are
substantially based on the prototypical qualities
of the group: They accept in their self-definition
those qualities—such as attitudes, values, actions, and appearances—that typify the group.
When members’ social identities align to match
the group’s prototype, they and their relationships
with one another become depersonalized: They
view themselves and their fellow members as
relatively interchangeable parts of the whole.
This process, Hogg (2001) concludes, leads to
cohesion by imbuing “ingroup members with
attributes of the generally evaluatively positive
ingroup prototype” and thus “accentuates
prototype-based liking” and “extends positive
self-regard to fellow members” (p. 66).
Recent research is, in general, consistent with
this reinterpretation of cohesion. Some studies,
for example, suggest that it is members’ identification with their groups that are responsible for
many of the positive consequences of group
membership previously attributed to cohesion.
Wann et al. (2017), for example, in their studies
217
of the positive effects of commitment to sports
teams, conclude that identification with teams
leads to both temporary and more enduring social
connections among the members, increased sense
of belonging, as well as more presence of meaning in their lives. Marmarosh et al. (2005), in a
study of members of therapeutic groups, found
that group cohesion and member’s identification
with their group (as indicated by the Collective
Self-esteem Scale) were highly correlated
(+0.78), and that both were negatively associated
with levels of depression. In Johnson and
Avolio’s (2019) study of task-focused groups,
both group identification and psychological
safety declined when groups experience elevated
levels of relationship, task, and process conflict.
The empirical record also indicates, however,
that high levels of identification are associated with
an increased tendency to denigrate individuals who
are members of other groups—the in-group–outgroupbias (Amiot& Sansfaçon,2011;Yampolsky&
Amiot, 2013). Identification, if extreme, can also
result in overidentification (Avanzi et al., 2020)
and prompt members to engage in extreme behaviors on behalf of their groups (Swann et al.,
2012). However, cohesion, when based on identity, is a more scalable concept, for it can be applied
to any group irrespective of size. Hogg (1992,
p. 149) concludes “we can now quite sensibly
discern cohesiveness in all sorts of groups, ranging
from small, interactive, task-oriented groups to
large-scale social categories.”
A Unitary Theory of Group Cohesion
Why do some groups succeed in reaching their
goals, but others fail? What are the key ingredients to include in a group experience that helps
members achieve personal change? When does
membership in a group cause a person to change
their conception of who they are? Theorists and
researchers have made substantial progress in
answering these important questions, often by
considering group cohesion’s influence on all
these processes. Any review of recent work
examining cohesion, however, cannot overlook
the definitional, measurement, and theoretical
uncertainties that continue to dog this concept.
Burlingame et al. (2018) judge cohesion to be
“the most popular of the relationship constructs in
the group therapy literature” (p. 384) but they
also note that “the construct validity and criterion
validity of cohesion measures are weak” (p. 393).
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218
FORSYTH
Dion (2000, p. 21) laments “At present we have
little or no idea as to how different putative
measures of cohesion in our current toolbox relate
to one another.” Von Treuer et al. (2018) conclude “cohesion is a complex construct and
current frameworks of cohesion may be too simplistic for capturing its true complexity.” These
empirical and theoretical uncertainties pertaining
to cohesion can be traced to a number of sources,
including a marked diversity in the number of
ways theorists and researchers have defined and
assessed the concept.
Cohesion Defined
The concept of cohesion, given its theoretical
importance and complexity, has been defined and
redefined by dozens of different theorists.
Festinger et al. (1950) initially considered cohesion to be a set of forces that combine to keep
individuals in the group, but they focused their
attention on one force more than all others:
Feelings of attraction that link members together.
Some subsequent researchers followed their lead,
but others considered the essence of cohesion to
be group pride, a shared identity, attachment,
collective efficacy, social network density, and
so on; a sampling of definitions is offered in
Table 1.
As more contenders emerged to lay claim to the
most accurate definition of cohesion, singlefactor definitions gave way to multicomponent
models that suggested that cohesion has multiple
facets. Mullen and Copper (1994), for example,
examined the elements identified in some of the
earliest conceptions of cohesion: Interpersonal
attraction, task commitment, and pride in one’s
group. Von Treuer et al. (2018), using inductive
procedures, concluded cohesion includes at least
six distinguishable components: Commitment to
goals, identify and respect, interpersonal warmth,
a sense of belonging, pride in the group’s achievements, and a shared positive group-level identity.
Carron and his colleagues, in their work with
sports teams, considered cohesion to be based on
social attraction, engagement in the group’s tasks,
and members’ beliefs about the group’s social and
task unity (e.g., Carron & Brawley, 2000). Bollen
and Hoyle’s (1990) two-dimensional model of
perceived cohesion includes a sense of belonging
and feelings of morale. Theories of solidarity
identify six elements that define intergenerational
unity: Associational, affectual, consensual, functional, normative, and structural (e.g., Bengtson &
Roberts, 1991). Adding further complexities by
Table 1
A Sampling of Definitions of Cohesion
Source
Definition
Festinger (1950, p. 274)
Cohesiveness of a group is here deemed as the result of all the forces acting on the members
to remain in the group. These forces may depend on the attractiveness or unattractiveness
of either the prestige of the group, members in the group, or the activities in which the
group engages.
The cohesiveness of small groups is defined in terms of intermember attraction : : : that
group property which is inferred from the number and strength of mutual positive attitudes
among the members of a group.
The degree to which the members of the group desire to remain in their group.
Perceived cohesion encompasses an individual’s sense of belonging to a particular group
and his or her feelings of morale associated with membership in the group.
Relational cohesion [is] the sense of coming together, of something larger that unifies actors
and actions.
The essence of strong primary group cohesion : : : is trust among group members (e.g., to
watch each other’s back) together with the capacity for teamwork (e.g., pulling together to
get the task or job done).
Cohesion is now generally described as group members’ inclinations to forge social bonds,
resulting in members sticking together and remaining united.
A multidimensional construct with six cohesion dimensions, comprising one task and five
social elements: : : : (a) commitment to goal, (b) identify and respect, (c) interpersonal
warmth, (d) belonging, (e) proud of team success, and (f) proud of team identity.
The sense of unity and attachment to the group.
Lott and Lott (1965,
p. 259)
Cartwright (1968, p. 91)
Bollen and Hoyle (1990,
p. 482)
Thye et al. (2002, p. 146)
Siebold (2007, p. 288)
Bakali et al. (2010,
p. 368)
von treuer et al. (2018,
p. 108, 123)
Marmarosh and Sproul
(2021, p. 171)
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UNIFIED COHESION THEORY
considering multiple levels of analysis, some theorists note that cohesion has both instrumental
(task) functions and interpersonal (social) functions,
but that these bonding processes occur across two
levels: Between rank-and-file group members—
horizontal cohesion—and between group members
and their leaders—vertical cohesion (e.g., Severt &
Estrada, 2015).
Additional research will be needed to resolve
this definitional debate, but one possible solution
lies in an integrative model of cohesion that draws
from both single-factor and multicomponent
models. Such a hybrid, unitary cohesion model
considers a group’s cohesion to be a singular,
indivisible aspect of a group but recognizes multiple antecedents that combine to determine group
unity. However, rather than including these antecedent conditions, such as interpersonal attraction, task commitment, or identity, in the
definition of group cohesion, the single-factor
model narrows the meaning of cohesion to focus
on only one question: To what degree is the group
a unified one? In chemistry and physics, when a
substance is cohesive the particles that constitute
it are bonded together to form a single, unified
entity that resists division. Similarly, a cohesive
social group is one that has achieved solidarity: It
is a unified alliance; a Gestalt; an integrated
whole.1 Morale might be high in such groups,
members may enjoy interacting with one another,
and they may resist leaving the group to join
another group—but these qualities are not cohesion. Cohesion is just a group’s degree of unity. A
cohesive group is a strong alliance and is considered to be strongly bonded, tight-knit, and unified. A group that is low in cohesion is one that is
weakly bonded, lacking in unity, low in member
commitment, and divided.
Sources of Cohesion
A unitary approach distinguishes between the
causes (or antecedents) of that unity (such as attraction bonds or group pride), indicators of cohesion,
and cohesion itself. It, therefore, draws on the
multicomponent models of cohesion to identify
the sources of a group’s unity but assumes that
no one condition or process is a necessary or
sufficient condition for a group to become cohesive.
As system’s theory principle of equifinality suggests: “A system can reach the same final state, from
different initial conditions and by a variety of
different paths” (Katz & Kahn, 1978, p. 30). In
219
consequence, what unifies the members of one
group may not unify the members of another.
Nonetheless, multicomponent models of cohesion have identified a number of processes that are
generally associated with cohesion. Group cohesion increases, for example, when members’
liking for one another strengthens, they identify
with the group and its purposes, when they
experience positive emotions when in the group,
when the group’s role patterns are well defined,
and so on. These influences on a group’s cohesion
are summarized in Table 2 and discussed below,
but with the caveat that this listing is illustrative
rather than comprehensive.
Interpersonal and Group Attraction
Lott and Lott (1965), in their seminal review of
studies of cohesion, defined cohesion as interpersonal attraction: To what extent do the members
like one another? They, therefore, suggest that
any variable that influences attraction, including
attitude and value similarity, propinquity, the
provision of rewards, and manifesting qualities
regarded as admirable, will influence members’
liking for one another. They accept Allport’s
(1962) structuronomic conception of group processes, who concluded “When the group dynamicist speaks of the ‘attraction of the group for the
individual’ does he not mean just the attraction of
the individuals for one another?” (p. 23). Hence,
they recommended assessing cohesion sociometrically: Ask members to identify all their good
friends and then calculate the ratio of in-group
choices to out-group choices. A higher proportion
of mutual attraction bonds would also suggest
higher levels of cohesion.
In contrast to a focus on the strength of dyadic
bonds within the group (interpersonal attraction),
members of highly cohesive groups may also
positively value the group as a whole (group
attraction). Hagstrom and Selvin (1965), for
example, discovered that commitment to groups
was influenced by what they termed social
satisfaction—their satisfaction with the group
itself—and sociometric cohesion—the number
of close friendships between themselves and their
1
A cohesive group is a Gestalt, but this unitary conception
of cohesion does necessarily bind the theory to any additional
assumptions often accepted by a Gestalt approach, such as the
premise that a Gestalt is greater than the sum of its parts or that
the characteristics of the whole are not entirely determined by
characteristics of the individual elements (Wertheimer, 1938).
220
FORSYTH
Table 2
Antecedents of Group Cohesion
Component
Attraction
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Task commitment
Social categorization
and identification
Group affect
Group structure
Entitativity
Description and examples
The strength and number of attraction bonds among members and members’ attraction to the group
itself (e.g., members are friendly to one another; members express satisfaction with the group and
engage regularly in group activities)
The strength of the group’s focus on goal attainment (e.g., members are committed to the group’s
purposes; they consistently contribute to the attainment of group goals; members are highly
motivated)
Members consider themselves to be members of the group and their social identities are consistent
with the prototypical features of the group (e.g., members identify with the group; they display ingroup favoritism and intergroup differentiation; in-group relations are depersonalized)
The affective intensity of the group (e.g., morale, esprit de corps, positive affective tone; also, specific
group-level emotions, such as pride)
Aspects of the group that increase its structural integrity, including norms, roles, and intermember
relations (e.g., mutual attraction bonds, high density; roles and norms are well defined; membership
is stable)
The group is perceived to be a unified entity (members are similar to one another; experiences are
shared in common rather than individualized; members interact with one another frequently; the
group is boundaried)
group members. Similarly, Marmarosh et al.
(2005) found that individuals who valued their
group, as indicated by their responses to the
public subscale of the Collective Self-esteem
Scale, also rated their group more positively on
a generic index of group cohesion. Attractionbased cohesion, then, increases when the number
of positive mutual relationships among members
increases, but also when the number of group
members who positively value the group rises.
the relationship between the level of interpersonal
friction in the group and both group performance
and social (attraction-based) cohesion. Conflict,
as predicted, lowered levels of task cohesion, and
as task cohesion declined so did decision accuracy
and social cohesion. This result may have resulted
from the improved communication among the
members as they worked at the task. McLaren
and Spink (2020) found that group members’
frequency of communication with multiple members of the group predicted both task cohesion and
the group’s overall performance.
Task Commitment
The unity of groups that form or are founded for
a specific instrumental purpose, such as juries,
sports teams, military squads, and crews, derives
from the members’ reliance on one another in the
pursuit of the group’s goals. Members of such
groups are often cohesive, not because of the
friendship bonds among members, but because
the members seek a common goal; they are therefore motivated to work together, as a unit, to
achieve that goal through coordinated group effort
(MacCoun et al., 2006). For example, Manata
(2016), in a study of groups experiencing conflict
while working on a hidden profile problem, assessed task cohesion directly with such items as
“our group was unified while completing the task”
and “members in this group worked well with each
other when completing the task” (p. 97). His
findings indicated that task cohesion mediated
Social Categorization and Identification
Recent studies of social identity processes in
groups, as noted earlier, trace a group’s degree of
cohesion back to members’ identification with their
group. Indeed, many measures of cohesion ask
members if they feel they belong to their group
(social categorization) or if they identify with the
group (social identity). Examples include “I think of
this group as a part of who I am” (Henry et al., 1999,
p. 572), “In general, being a [member of this group]
is an important part of my self- image” (Cameron,
2004, p. 244), “the fact that I am in [this group] is an
important part of my identity” (Leach et al., 2008,
p. 165), and “I am a [group member] and I will
remain one until I die” (Sundberg & Ruffa, 2021,
p. 95).WhenJacksonandSmith(1999)askedgroup
members to complete measures of both cohesion
UNIFIED COHESION THEORY
and group identification, items that were designed to
assess social identity were significantly correlated
with measures of group cohesion, so much so that
factor analysis indicated that measures of these two
theoretically distinct concepts loaded on a single
common factor.
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Group Affect
Some of the earliest investigations of group
processes, including contagion, conformity, and
motivation gain, suggested that the unity of
groups derives, at least in part, from such shared
emotional experiences as morale, élan, and esprit
de corps. Durkheim (1912/1965), for example,
noted the prevalence of ritualized interactions in
various types of groups and concluded that these
rituals result in elevated levels of both collective
emotion (collective effervescence) and cohesion.
More recently, George (1996), in her theory of
group affective tone, has argued that cohesive
groups tend to display collective mood states as
members’ emotions become synchronized. This
shared, consensual state often goes unrecognized
by the members, but when the group’s shared
affect is positive, group members are more likely
to act in pro-social ways, leader–follower relations are strengthened, and performance improves (Barsade & Knight, 2015).
Terry et al. (2000) directly examined the relationship between group mood and cohesion in
their analysis of netball, rowing, and rugby teams.
They discovered that as task cohesion declined,
members of these performance-focused groups
displayed higher levels of tension and anger.
They also found that lower levels of social cohesion were associated with a different set of emotional responses. As social cohesion declined,
players reported lower levels of positive affect,
reduced vigor but higher levels of tension and
depression.
Group Structure
As Tuckman (1965) noted in his seminal analysis of group development, groups become more
cohesive over time as their structures become
more stable, patterned, and disambiguated. The
third stage in his model of group development is,
after all, the “development of group cohesion
stage” (norming), when “the group becomes an
entity by virtue of its acceptance by the members,
their desire to maintain and perpetuate it, and the
221
establishment of new group-generated norms to
insure the group’s existence” (p. 386).
In social network terms, some groups are more
interpersonally dense than others: The ties linking
members are strong, durable, and numerous, with
the result that the group is a unified one.
Graupensperger et al. (2020), for example, used
social networking methods to index the density of
35 same-sex sports teams; they also calculated
egocentric indexes of group structure, such as outdegree and in-degree centrality. They discovered
that centrality was significantly associated with
members’ identification with the group (with
items pertaining to affect, interpersonal attraction,
and identity), but so was density, even after considering the individual-level effects of centrality.
The density of the group’s social network is
only one aspect of group structure that influences
its cohesiveness. As Friedkin (2004), in his review
of sociological studies of cohesion, writes: “A
large, complexly differentiated group, with members connected directly or indirectly (through
intermediaries) by paths of positive (weak or
strong) interpersonal ties, may be cohesive if
the group’s social network has particular structural characteristics” (p. 417). For example, open
groups—those with permeable boundaries—are
generally less unified than closed groups because
members remain in the groups for longer periods of time and so anticipate future collaborations (Ziller, 1965). When Burnette and Forsyth
(2008) experimentally manipulated the permeability of the boundaries of study groups in a
college course, they found that open groups
were not only less cohesive than the closed
groups, but their members were also less likely
to take leadership roles or personal responsibility for the group’s work.
Entitativity (Perceived Cohesion)
Some groups are more cohesive than other
groups because they look cohesive: Perceivers,
from their vantage point either inside or outside of
the group, conclude the group is a unified, intact
group rather than an aggregate of separate individuals. Campbell (1958) coined the term entitativity to describe this feature of groups and drew
on Gestalt principles of perception to identify
when perceivers will judge a group to be a unified
one. If, for example, the individuals act in
unison or display common features (similarity),
if they are physically close rather than separated
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222
FORSYTH
(proximity), and if the members all experience the
same or interrelated outcomes (common fate),
then perceivers are more likely to consider the
aggregate to be an entity rather than a collection of
individuals. Confirming the association between
cohesiveness and entitativity, Thurston (2012)
found that responses to such items as “do you
think about this collection of people as a number
of individuals or as a whole” were correlated with
both social cohesion (r = +0.55) and task cohesion (r = +0.67). He also found that qualities that
were associated with increases in entitativity,
such as the importance of the group for the
members, the amount of interaction among members, and the duration of the group, also predicted
increases in cohesion.
Studying Cohesion: The Next 25 Years
What does the future hold for the study of
group cohesion? One possible future predicts
more of the same; adequate but limited progress
in exploring the causes and consequences of
cohesion, but advancement hampered by continuing theoretical, definitional, and assessment
uncertainties. An alternative future, however, will
be marked by even more rapid scientific progress
as investigators make use of better-validated
methods of assessment and succeed in disentangling the causes and consequences of cohesion
from cohesion itself.
Cohesion as Group Unity
Definitions are consensual, and so the concept
of cohesion cannot be defined through edict.
When Alice encountered Humpty Dumpty in
Lewis Carroll’s (1872/1991) book Through the
Looking-glass, she took askance when he claimed
that he had an authoritative right to be the definer
of all words: “‘When I use a word,’ Humpty
Dumpty said, in rather a scornful tone, ‘it means
just what I choose it to mean—neither more nor
less.’” The definition of cohesion offered here is
only one definition. Its narrowed focus, on the
degree of unity of a group, limits the comingling
of causes of cohesion with their effects, but like all
arbitrary pronouncements of meaning, its validity
is debatable. A unitary model of cohesion holds
promise for consolidating previous approaches to
defining cohesion, but research is needed to
determine its utility.
Cohesion is a Group-Level Construct
A group’s level of cohesion is the result of
multilevel processes, for a group’s unity is determined by individual-level processes—members
liking for each other, their perceptions of the
group’s value, their degree of identification
with the group, and so on—but also by such
group-level processes as leadership, informational and normative influence, group density
and interconnectedness, and climate. Cohesion,
however, is a property of groups rather than
individuals (e.g., Whitton & Fletcher, 2014). Individuals may identify with their groups, like all
the members of their groups, or feel that they
belong to their groups, but these psychological
experiences are not cohesion. A lone individual
cannot experience cohesion, brainstorm, or be
overtaken by groupthink: These are all grouplevel processes.
Assessing Cohesion
Even if it can be agreed that cohesion is best
defined as the degree of unity of a group, this
definitional compromise does not mandate uniformity in the methods of assessing a group’s
cohesion. Any number of observable qualities
of a group may serve as proxy indicators of the
group’s unity. Social network analysis provides
an index of the group’s density, but cohesion can
also be inferred from the number of isolates or
disliked members in the group, the ratio of strong
to weak ties, and other topological features (e.g.,
transitivity, reciprocity, average betweenness). A
group’s durability may also indicate its unity:
Does the group remain intact even when it encounters disruptive influences? Is the membership
stable over time? Does the group deal with conflict
effectively (e.g., Marmarosh, 2021)? Cohesion
can also be intuited from direct observation of
the group’s communication and interaction patterns, as language use, influence tactics, conflict
levels, and modes of resolving conflict likely
differ systematically in relationship to a group’s
cohesion. For example, language convergence, a
high level of engagement, the use of group-level
pronouns, behavioral synchrony and mimicry,
and the affective tone of the contents of
intragroup communication may all serve as
indirect indicators of cohesion (Van Swol &
Kane, 2019).
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UNIFIED COHESION THEORY
Researchers will, however, likely continue to
rely on individual-level data gathered through
self-report measures to assess group cohesion.
Researchers have developed an extraordinary
number of inventories to assess cohesion, such
as the Child Sport Cohesion Questionnaire
(Martin et al., 2012), Group Attitude Scale
(Evans & Jarvis, 1986), Group Climate Questionnaire (MacKenzie, 1983), Group Environment Questionnaire (Carron & Brawley, 2000),
Harvard Group Cohesiveness Scale (Budman et al.,
1989), Perceived Cohesion Scale (Bollen & Hoyle,
1990), and the Therapeutic Factor Inventory–
Cohesion subscale (Lese & MacNair-Semands,
2000). These inventories, however, tend to confound
cohesion—as group unity—with the source of that
unity, such as liking for the group or commitment to
the group’s tasks, and this focus should be documented to (a) facilitate the systematic aggregation of
research findings and (b) avoid overestimating the
strength of the association between concepts and
processes by measuring them with overlapping items
(Suddaby, 2010). A measure that focuses only on
group members’ perceptions of their group’s cohesiveness, for example, may be assessing something
very different than a measure that focuses on their
degree of identification with the group. Moreover,
when measures rely on individual-level data to make
inferences about a group-level state, the methodological procedures summarized by Bonito and
Keyton (2019)—multilevel confirmatory factor
analysis, intraclass correlational analysis, and multilevel modeling—should be utilized.
Researchers could also include in their studies items that assess the narrowed conception
of cohesion posited by unitary cohesion theory. One such measure is included in the
Appendix: The Unitary Cohesion Index
(UCI). The items on the UCI ask respondents
to rate their group on a set of 10 bipolar
adjectives, including strongly bonded/weakly
bonded, sticks together/drifts apart, tight-knit/
loosely linked, and togetherness/separation.
When paired with existing measures of group
cohesion, the UCI may provide an empirical
basis for (a) determining the strength of association between group and individual factors
that influence cohesion, (b) comparing existing
measures of cohesion to one another, and
(c) identifying additional causes and indicators
of cohesion. (The Supplemental Materials provide more information about the scale’s development and psychometric properties.)
223
Conclusion
In 1951 Schachter and his colleagues, in
examining the concept of cohesion, concluded
that analyses of “this group property have
been notably loose and cohesiveness has been
defined variously as referring to moral, ‘sticking togetherness,’ productivity, power, task
involvement, feelings of belongingness, shared
understandings of roles, and good teamwork”
(p. 229). The concept of cohesion is a critically
important one in the study of groups and its
processes, yet this description of the conceptual
turmoil surrounding the concept, written 70
years ago, remains true in 2021, as researchers
and theorists continue to debate the definition of
cohesion and disagree about the best way to
assess this critical group property. Looking
forward to the future of this concept in the field,
it is hoped that theorists and researchers will
reach a unified conception of cohesion, and
more precisely identify the antecedents and
consequences of group unity.
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Appendix
The Unitary Cohesion Index (UCI)
Please rate your group on the following word pairs by circling the number on each line that best
represents your beliefs about the group.
Strongly bonded
Unintegrated assembly
Sticks together
Distant
Tight-knit
Disconnected
Togetherness
Splintered
United
Loosely connected
:__5__:__4__:__3__:__2__:__1__:
:__1__:__2__:__3__:__4__:__5__:
:__5__:__4__:__3__:__2__:__1__:
:__1__:__2__:__3__:__4__:__5__:
:__5__:__4__:__3__:__2__:__1__:
:__1__:__2__:__3__:__4__:__5__:
:__5__:__4__:__3__:__2__:__1__:
:__1__:__2__:__3__:__4__:__5__:
:__5__:__4__:__3__:__2__:__1__:
:__1__:__2__:__3__:__4__:__5__:
Weakly bonded
An integrated whole
Drifts apart
Close
Loosely linked
Cohesive
Separation
Fused
Divided
Tightly connected
Note. Scores are calculated by summing the 10 responses, and so can range from 10 to 50. The average score in the
development sample was 36.41 (SD = 8.68), and the Cronbach’s α was .90.
Received April 22, 2021
Accepted May 23, 2021 ▪