4 Social Networks in Groups

Networks and relationships

A social network is a pattern of relationships among people or other actors. In a group, members are the nodes and their relationships are the ties. A tie can represent communication, advice, friendship, trust, authority, or collaboration. Because each kind of tie captures a different relationship, one group can contain several overlapping networks.

Network analysis examines not only who members are, but also how their connections shape access, influence, and coordination. Understanding a group therefore involves examining both its members and the relationships among them.

Formal and informal ties

Formal ties are established by an organization’s official structure. Supervisor–employee relationships, assigned project roles, and reporting lines are examples; these ties clarify responsibility and authority.

Informal ties emerge through everyday interaction, including friendship, advice-seeking, trust, and information sharing. They may help members solve problems quickly, but they can also create unofficial channels of influence or leave some people out.

Formal and informal networks overlap but do not necessarily match. A person may have little formal authority yet be the colleague others consult for expertise. Conversely, someone with a senior title may not be central to day-to-day communication. Understanding an organization requires asking both who is formally connected and who actually exchanges information or support.

Network structures and properties

Network structure describes how ties are arranged across a group. Common structures have different implications for communication and coordination:

• In a chain, members mainly communicate with those next to them. Messages can travel slowly and may change as they pass along.

• In a star, one central member connects to many others. Coordination can be efficient, but the group becomes dependent on that person.

• In an all-channel network, members communicate broadly with one another. This can support shared participation, though maintaining many connections may take time.

• In a clustered or modular network, members form close subgroups with fewer ties between them. Strong within-cluster connections can support trust, while links between clusters help ideas and information cross group boundaries.

Two network-level properties help describe patterns across a group. Density is the share of possible ties that actually exist. A dense group may share information readily. Centralization describes the extent to which ties or influence are concentrated around a few members; a highly centralized group may coordinate through a small number of key people. Neither density nor centralization is always best: the task, group size, and type of relationship matter.

Roles and centrality

Network positions can create informal roles. A broker connects people or subgroups that otherwise have few ties. A boundary spanner links the group to outsiders. A peripheral member has relatively few connections. These positions affect access to information and opportunities, but do not automatically determine a person’s skill, status, or contribution.

Centrality describes how prominent or strategically placed an actor is in a particular network. Different measures capture different kinds of position:

• Degree centrality counts direct ties. In a directed network, incoming ties, such as requests for advice, and outgoing ties, such as advice given, can be counted separately.

• Betweenness centrality measures how often a person lies on shortest paths between others. A member with high betweenness may connect otherwise separate subgroups and control or facilitate information flow.

• Closeness centrality describes how near a person is to other members by network paths. Higher closeness can indicate the potential to reach others quickly.

No single centrality score defines someone as the group’s leader. Individual centrality describes a member’s position, whereas network centralization describes how unevenly centrality is distributed across the group.

How networks shape group behavior

Networks shape which information reaches whom, how quickly it travels, and whose views are heard. Repeated interaction can build trust and shared expectations, supporting cooperation. Close ties can also reinforce existing opinions, while weak ties may connect members to less familiar information or other groups. A tightly knit subgroup can provide support but may become isolated if it lacks bridges to the wider network.

Network position can affect influence and power. A central member may be well placed to circulate information, while a broker may connect distinct teams or control a communication bottleneck. These advantages also carry risks: overdependence on one connector can slow work when that person is unavailable, and divisions between subgroups can produce information gaps.

Network patterns do not determine behavior by themselves. The content and direction of ties, group norms, task demands, and members’ choices also matter.

A project team example

In a project team, the official chart names one person as coordinator, but members routinely ask a technical specialist for advice. The coordinator has a formal role, while the specialist has informal influence in the advice network.

If the specialist is the only person linking two subteams, they also occupy a brokerage position. Sharing expertise across the teams may improve coordination, while relying exclusively on that one link creates a bottleneck.

Putting network patterns together

Groups contain overlapping formal and informal networks. Structures such as chains, stars, and clusters shape communication, coordination, cohesion, and access to information. Centrality measures describe different kinds of network position, while brokerage and other network roles can connect or separate subgroups. To understand group behavior, examine both the relationships members are expected to have and the ties they actually use.