Who’s right? Jeff Bezos says ‘no more than “8” (for team meetings), popular research says it’s “4.6”, agile scrums max out at “10”, whilst Dunbar's Number restricts the amount of relationships we can manage closely to between 5 and 15.
There’s been plenty of research over the years. In the early 1900s, French engineer Maximilien Ringelmann tested teams of different sizes by having them pull on a rope. He found that as the number of participants increased, each individual's effort declined. Essentially, the bigger the group got, the less energy each person put in.
Let's begin the search with this perhaps counterintuitive insight: smaller teams often outperform larger ones. There's plenty to unpack - psychological, sociological, and organizational science behind why smaller teams can be more effective.
1. The Coordination Conundrum
One of the more substantial challenges larger teams face is coordination. The bigger the group, the more complex it becomes for individuals to synchronize tasks, align goals, and communicate seamlessly. Not to mention the technology needed to activate a team.
Communication Overload: In larger groups, multiple communication channels can cause information overload. According to communication theory, the number of potential communication lines in a group is n×(n−1)2\frac{n \times (n - 1)}{2}2n×(n−1). A team of six has 15 potential communication lines; a team of twelve has 66. As teams grow, the complexity increases exponentially.
Above: It’s easy to see why larger teams suffer. The complexity of a network grows logarithmically with each person you add.Loss of Shared Mental Models: Smaller teams are more likely to maintain a shared mental model—an aligned understanding of roles, responsibilities, and objectives. In larger teams, it becomes easy for subgroups to form, creating misalignment and information silos.
Research Insight: Studies on organizational behavior have found that excessive team size often leads to longer decision-making processes and an increase in misunderstandings—both of which hamper performance.
2. Social Loafing and Accountability
A well-documented phenomenon in psychology and group behavior is social loafing, also known as the “Ringelmann effect.” It describes how individual effort can decrease as team size increases.
Reduced Personal Accountability: In larger teams, it’s easy for members to “hide” because individual contributions are less obvious. When a person senses their effort is less likely to be noticed, they might unconsciously exert less effort.
Greater Ownership in Smaller Teams: With fewer people, each member’s responsibilities and contributions are more visible, leading to a heightened sense of accountability and personal ownership of tasks.
Research Insight: In classic experiments, when participants were asked to pull on a rope or clap in groups, the individual force or volume exerted decreased as the group size grew. By contrast, smaller teams consistently reported higher engagement levels and clearer personal accountability.
3. Psychological Safety and Trust
Psychological safety—the shared belief that one will not be punished or humiliated for speaking up with ideas, questions, or concerns—is essential for teams that want to innovate and problem-solve effectively.
Building Trust More Easily: In smaller teams, it’s simpler to establish interpersonal trust. Individuals get to know each other’s work styles, personal strengths, and weaknesses more intimately, fostering closer bonds.
Faster Conflict Resolution: Conflicts are inevitable in any team, but with fewer members, issues can be addressed more quickly and personally, often preventing problems from escalating.
Research Insight: Studies at Google on effective teams found that psychological safety was the number one predictor of high performance. Smaller teams often naturally cultivate this environment by default, as trust and mutual understanding can be developed quickly and maintained more easily.
4. Cognitive Load and Decision-Making
Team-based decision-making can be both an asset and a liability. On one hand, groups can pool their expertise to make well-rounded decisions. On the other, large groups can suffer from “analysis paralysis,” where too many voices and too many opinions stall progress.
Agile and Iterative Decisions: Smaller teams can pivot faster, re-evaluate more frequently, and make decisions without wading through layers of approval or hierarchy. This agility is particularly beneficial in dynamic industries (e.g., tech, startups) where time-to-market is crucial.
Clearer Group Goals: With fewer team members, the team’s purpose and tasks are more straightforward. This clear focus can reduce cognitive load, preventing burnout that often arises from constantly juggling overlapping or ambiguous responsibilities.
Research Insight: Organizational psychologists have noted that decision-making quality and speed often peak at a certain threshold—beyond which each additional member contributes diminishing returns or even negative effects.
5. Creative Collaboration in Small Groups
Innovation often emerges from close-knit, flexible teams. When members can share ideas openly, iterate rapidly, and “fail fast,” creativity flourishes.
Brainstorming Efficiency: In smaller, psychologically safe groups, brainstorming sessions tend to be more focused. Ideas can be tested quickly without being diluted by the complexity of managing multiple participants.
Adaptive Problem-Solving: Team members in smaller settings are more likely to take on multiple roles and have cross-functional insights, leading to novel solutions.
Research Insight: Dunbar’s Number, a theoretical limit proposed by anthropologist Robin Dunbar, suggests that humans maintain stable social relationships with up to around 150 people, with much smaller subgroups forming tighter bonds. Within smaller teams, these closer relationships can enhance creative synergy and shared understanding.
6. The Two-Pizza Rule and Optimal Team Size
Jeff Bezos, founder of Amazon, famously coined the “two-pizza rule,” suggesting that a team should be small enough to be fed with two pizzas. While this is a playful guideline, it points to a broader principle of maintaining lean, focused teams.
Finding the Sweet Spot: The “optimal” team size varies by context—some research suggests 5 to 8 is ideal for many knowledge-based tasks, but this can vary based on the complexity of the project, the diversity of skills needed, and the organizational culture.
Balancing Perspectives and Cohesion: Leaders must ensure there’s enough diversity in skills and backgrounds to generate fresh insights, but not so many people that group cohesion and accountability become diluted.
Above: Research conducted by Hackman and Vidmar concluded that the ideal team size was 4.6.
Above: Research conducted by Ivan Steiner suggested that productivity begins to decline after more than 5 people are added to a team.
7. Practical Tips
Clearly Define Roles and Responsibilities: Even in a smaller team, clarify each member’s domain. Overlapping tasks can lead to confusion if not explicitly addressed. Note: A team does not necessarily need a leader and in some cases can be counter productive.
Regular Check-Ins: Hold short, structured stand-up meetings to ensure alignment. When there are fewer people, these meetings can be quick yet highly effective.
Foster Psychological Safety: Encourage open dialogue, active listening, and a culture where challenging ideas are seen as constructive rather than threatening.
Empower Decision-Making: Push autonomy and decision-making authority down to the team members doing the work. Smaller teams can leverage this autonomy to move quickly.
Monitor Workload: Smaller teams can risk burnout if they are consistently overextended. Regularly evaluate workloads to maintain a sustainable pace.
Celebrate Successes: Recognize both individual and team achievements to keep motivation high and reinforce collaboration.
Tools and Systems: Using the right tools can assist a team but also cause distraction. It is important to weigh up the ease of use within a team, especially if they are remote, or lack IT skills and balance this with the business requirements for security and compliance.
Why 8seats?
8seats is a communication platform which enables easier team collaboration. It enhances a team’s ability to connect and collaborate effortlessly in a simple interface, with minimal restrictions.
Please note that 8seats is not restricted to eight team members (although the basis for our systems follow much of the research in this article).
8seats Table system supports single teams up to 20 people (2 million combinations of conversations and 10,000 people in rooms, enabling several teams to come together in one spot, and large and small businesses to operate by managed ‘rooms / tables / D.M.
Conclusion
Science consistently supports the notion that small teams can be more agile, accountable, and creative than their larger counterparts. By minimizing management overhead, fostering stronger interpersonal relationships, and encouraging personal accountability, organizations can reap the benefits of empowered, tight-knit groups.
There is no absolute universal “magic number” for all organizations or all tasks. The optimal team size will depend on the nature of the project, the skill diversity required, and the cultural context of the organization.
In conclusion, and also based on our own findings, small teams of between 5 and 8 people are optimal for tackling tasks and projects, this includes those inside larger organisations. Larger groups play important roles within a company culture to create community so fine tuning the balance between 'big teams/communities' and the 'small teams to get stuff done' is important.
References & Further Reading
Hackman, J. R. (2002). Leading Teams: Setting the Stage for Great Performances. Harvard Business School Press.
Ringelmann, M. (1913). Recherches sur les moteurs animés: Travail de l'homme. Annales de l'Institut National Agronomique.
Edmondson, A. (1999). “Psychological Safety and Learning Behavior in Work Teams.” Administrative Science Quarterly, 44(2), 350-383.
Dunbar, R. I. M. (1992). “Neocortex size as a constraint on group size in primates.” Journal of Human Evolution, 22(6), 469–493.
