Why teams split into rival groups

A team that looks like two teams during meetings

After two departments merge, half the group consists of experienced head-office employees and the other half of recently hired remote specialists. The first group knows the company’s history and communicates face to face. The second uses different tools and lives in different cities. Age, tenure, location, and ways of working begin to align. When a process dispute arises, it is easy to hear, “They want to change everything again,” or “The people at headquarters never listen to us.” A single decision becomes a test of camp membership. Researchers describe such potential boundaries as team faultlines: patterns of attributes that can divide a team into relatively coherent subgroups. This differs from diversity itself. If people with different levels of tenure work in different locations but share interests across those boundaries, the divisions may cut across one another. If every difference points to the same line, it becomes easier to tell a simple story about two opposing groups. This remains a possibility, not a verdict on the team’s future. It is therefore not enough to count the number of differences in a team. Their configuration matters. If people from one department also have similar tenure, work in the same location, and mainly communicate among themselves, the boundary may become more distinct. When similarities cut across the team in different directions, people have more opportunities to discover common ground with colleagues outside their immediate subgroup. This is a way to understand a possible mechanism, not a basis for predicting conflict from a staffing table. Any actual division must be confirmed through patterns of contact, information exchange, and decision-making. A team may differ in many ways and still collaborate effectively on a clearly defined task.

A potential faultline does not have to become a conflict

Distinguish the structure of differences from the activation of those differences in everyday interactions. Two departments can have different areas of expertise and work well together until that difference becomes the basis for exclusion or competition for recognition. A reorganization, competition for resources, or a leader who repeatedly contrasts “old” and “new” employees may all matter. In our example, remote work alone does not explain the tension. We also need to examine who participates in decisions, where information circulates, and how different proposals are interpreted. A meta-analytic integration of the literature by Thatcher and colleagues demonstrates the complexity of research on team faultlines. A review by Zhang and Chen, in turn, examines subgroup formation and the quality of interaction. A shared practical implication is the need to examine collaborative processes, not just demographic composition. A list of differences alone does not explain what people do with them. Teams should therefore not be characterized as conflict-prone based on the age, gender, or background of their members. Thatcher et al., 2024; Zhang and Chen, 2023.

How a division takes on a life of its own

One early sign may be an asymmetry in interpretation. We explain a mistake by someone in our own subgroup as the result of being overloaded, but treat the identical mistake by someone on the other side as proof of incompetence. Another sign concerns the flow of information: a message goes to “our people” first and reaches everyone else only later. Such behavior can strengthen a boundary even when no one has formally prohibited collaboration. Subgroups begin to develop different pictures of the situation, and later misunderstandings reinforce the belief that the other side operates differently and cannot be relied on. However, not every close relationship within a subgroup is a problem. People who perform similar tasks need frequent contact and may form effective communities of practice. The question is whether those ties leave routes open for collaboration beyond the subgroup. A specialist discussion channel is different from a hidden decision-making loop that affects the entire team. A sound analysis distinguishes a justified concentration of expertise from a situation in which group membership determines access to influence and the ability to act. The division becomes especially consequential when each side begins to explain the other’s behavior in terms of camp membership. A coworker’s mistake is no longer an individual error; it becomes proof that “they always work that way.” People then assess their own group in detail and consider the circumstances, while reducing the other group to a shared label. Information that remains confined to subgroups can provide another practical warning sign. If meeting participants agree on positions only within their own circles beforehand, the discussion can easily turn into a presentation of fixed battle lines. This does not mean that every internal departmental consultation is inappropriate. Examine whether it helps prepare evidence or instead makes it harder to consider arguments together and revise positions later.

What a leader can change about how work is organized

Tasks in which collaboration across the boundary serves a genuine purpose can help. Pair people from different parts of the team and make them jointly responsible for a specific outcome, with a shared goal and the resources they need. Symbolically mixing seats at a workshop is not enough if decisions continue to be made within a single circle afterward. In the reorganization described above, it could be useful for someone who knows the company’s history and someone bringing new solutions to design the process together, with clearly defined responsibilities. Equal access to information is just as important. Agreements reached during an informal kitchen conversation should be transferred to a channel accessible to everyone concerned. Leaders can also examine their language: Are they describing the specific needs of the task, or using group labels? Instead of saying, “The new people need to adapt,” identify the standard at issue. Instead of saying, “Headquarters is blocking us,” name the decision and its rationale. This precision makes it harder for a disagreement about a solution to turn into a judgment of an entire group.

How to assess progress without labeling people

Observe whether information moves between subgroups, who consults whom when problems arise, and whether different people have influence over agreements. There is no need to rank employees by “openness.” Questions about specific obstacles are more useful: Where did the task stall? Who was not invited? Which communication channel failed? If collaboration becomes easier after the rules change, that says more than a declaration that the team “values diversity.” Behavior shows whether boundaries are permeable. A shared task should require genuine integration of contributions, not merely place people on the same calendar. For example, ask people from different parts of the team to prepare one solution together, while defining responsibility and the process for resolving doubts. Do not shift all the work of connecting groups onto one person acting as an intermediary. Over time, that employee may become overloaded or be suspected of disloyalty by both sides. It is better to create several direct relationships grounded in specific tasks. Then check whether agreements circulate more broadly and whether discussions include arguments focused on the problem itself. Simply declaring that everyone is now one team does not change existing dependencies.

Differences become especially important when they align along a single boundary and begin to determine access to information and influence. A leader does not need to eliminate differences. They can create conditions in which employees have reasons, opportunities, and clear rules for collaborating across divisions.

Using Empatyzer to discuss divisions within a team

Empatyzer can help you examine the differences and similarities worth considering when organizing collaboration. The Similarity map displays patterns across the available profiles, but it is not a map of actual coalitions, friendships, or conflicts. You vs. the team can also help you notice where your own way of working differs from the group pattern. Use this information to formulate questions, not to assign employees to camps. In Talk to Em about your team, you can prepare communication about a shared goal, rules for exchanging information, and ways to discuss differences. The leader must combine this work with observations of real interactions and conversations with team members. Em cannot determine whether a division is active or who is responsible for sustaining it. It can support language that avoids group labels and redirects the conversation to specific needs, dependencies, and responsibilities within the project.