A template to help assess the size of groups in an organization in relation to Dunbar number trust boundaries. Based on some of the ideas in the book Team Topologies by Matthew Skelton @matthewskelton and Manuel Pais @manupaisable.
See teamtopologies.com for more details about Team Topolologies.
Copyright © 2018-2020 Team Topologies - Licenced under CC BY-SA 4.0
Human groups exhibit several "trust boundaries" (or "social inflection points") that limit and enable degrees of trust within the group. Military groupings have evolved over thousands of years to the present size limits of around 8, 30-50, and 100-150 personnel in a group. The manufacturer W.L.Gore has for decades limited the size of factories and offices to 150 people to maintain high trust within each location. Similarly, in 1992 anthropologist Robin Dunbar characterised a limit of around 150 people as the maximum social network size that humans can maintain. Recent research from Emily Webber and Robin Dunbar suggests these historical social trust boundaries are also present in work contexts, specifically Communities of Practice.
For organizations to be highly effective, they need to take account of these "Dunbar number" trust boundaries when growing, when aligning teams to work, and when considering spheres of influence. Groups within an organization that grow in size beyond one of these trust boundaries are likely to have difficulty maintaining cohesion and trust, leading to and "us and them" attitude and reduced effectiveness.
Identify the size of different groups within your organization. For each group, determine whether the group size is close to a trust boundary or whether the group size falls between two trust boundary sizes.
Groups that are slightly smaller than the trust boundary are likely to have good trust in relation to the number of people; groups that are somewhat larger than the trust boundary are likely to have problems with low trust in relation to the number of people - these groups are candidates for splitting into smaller groups.
| Group name | Group size (people) | Closest trust boundary | Likely trust problems? |
|---|---|---|---|
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Group trust boundaries ("Dunbar numbers"): 5-8, 15, 50, 150, 500, 1500