When your business grows, Something Changes.
Most Business Owners Don't See It Until It's Too Late.
There's a moment in the growth of most small businesses that nobody warns you about. You've built something real — a team that works hard and gets things done. Then somewhere between ten and fifty employees, something quietly shifts. The energy changes. Silos appear. People seem less connected to the whole.
What's happening isn't dysfunction — it's science.
How Groups Form as Your Business Grows
Psychologist Robin Dunbar's research on human social cognition (1992) found that we are only capable of maintaining genuinely close, trust-based relationships with around 15 people at a time. Beyond that threshold, relationships become more transactional. At work this results in weaker collaboration, reduced information flow, slower conflict resolution, and reduced psychological safety.
This plays out predictably as a business grows:
At ten employees, most people have meaningful relationships across the whole team.
By twenty, informal clusters begin to form — often organised around shared roles, physical proximity, or who people spend the most time with.
By thirty to fifty, these clusters solidify into something more defined: distinct subgroups with their own norms, shared language, and sense of identity.
This isn't a leadership failure. It's a natural human response to scale. The challenge is what happens next.
In-Groups, Out-Groups, and the Culture Beneath the Culture
Henri Tajfel's Social Identity Theory (1979) shows that once people identify with a subgroup, loyalty to that group quietly begins to compete with loyalty to the organisation. People start to favour those in their group — sharing information more freely, advocating for their interests, interpreting the actions of other groups with more suspicion.
This is the in-group/out-group dynamic, and in a growing business it can be corrosive:
A culture that once felt cohesive can start to fracture along invisible lines.
Long-tenured staff can develop resentment toward newer employees.
A manager's inner circle has the potential to become a source of perceived favouritism.
People can even stop raising concerns across group boundaries.
The interpersonal cost is significant — increased conflict, reduced collaboration, and a sharp decline in psychological safety. Research consistently links these dynamics to business cost, slower decision-making, higher turnover, and reduced overall performance. Outcomes no growing business can afford.
What Should Business Owners Do?
The good news is that small businesses still have meaningful leverage here — but it requires intention.
Define behaviour we want. You can work with your managers and leaders to define what behaviours we want to see and those we don’ot. Observable behaviours, communicated then role modelled daily can break down some of the opportunity for counterproductive behaviour to take hold.
Make the whole visible. Create genuine touchpoints across subgroups — not forced social events, but structured opportunities for cross-team collaboration and shared problem-solving. When people work toward a common goal together, group boundaries soften.
Reinforce what you want to see. Celebrate behaviours that serve the whole business, not just individual teams. When leaders visibly reward cross-group cooperation, it signals clearly where loyalty should sit.
Address fragmentation early. When you notice a subgroup developing an us-versus-them narrative, don't wait. Name it, explore it, and reconnect people to the broader purpose. Culture doesn't fracture overnight — but it does fracture quietly.
Invest in your managers. In a business where managers are leading teams, culture is largely delivered through them, the leaders of each subgroup. Their ability to model inclusive behaviour, manage conflict constructively, and maintain psychological safety is one of the highest-leverage investments you can make.
What does getting this right actually look like?
When leaders get ahead of subgroup dynamics, the difference is tangible. Teams that once operated in silos start to share information more freely. Decisions get made faster because people trust the process — and the people around them. Conflict, when it does arise, gets resolved at the team level rather than escalating. And perhaps most importantly, people feel like they're part of something bigger than their immediate group. That sense of belonging is what drives discretionary effort — the kind that doesn't show up in a job description but makes an enormous difference to how a business performs. For a growing business, that's not a soft outcome. It's a competitive advantage
At Ascent People Insights, we work with growing businesses to identify where subgroup dynamics are forming, and help leaders intervene before they become a constraint on performance.
Want to talk about how this applies to your team? Get in touch.