Robin Dunbar, anthropologist and author of works such as, “How many friends does one person need?”, made an fascinating discovery when looking at primate brain size and social capacity. He noticed patterns in the numbers of primates that formed small close units and bigger communities and so explored if these numbers work in human social groups too. He trawled historical records, archaeological data, military units and church congregations, and repeatedly found the same numbers.

And so “Dunbar’s number” was created. This is the idea that there is a cognitive limit as to how many stable relationships humans can maintain. (Spoiler alert, it’s around 150.) Why? Because we can only spend time with a certain number of people on a social level, and social behaviours that synchronise bodies, (laughter, singing, moving together, sharing food) engage the endorphin system that dampens stress and deepens affiliation.

Dunbar expanded his findings to explain the different social circles that humans naturally fall into:

• 5 people: Your inner circle of closest friends and family who provide support.

• 15 people: Your “sympathy group” of a broader circle of close friends and relatives.

• 50 people: The “affinity group” of friends, extended family, or colleagues you maintain meaningful relationships with.

• 150 people: The “full active network” of people with whom you can realistically maintain stable, meaningful connections.

These layers carry contact rhythms too: your inner circle needs weekly touch whereas your outer rings need a lighter, regular cadence.

These circles are absolutely represented in organisations. My client with her 15-strong “team” will see that over time the group will naturally split into three closer factions of 5. Or people may start to feel left out as an “inner circle” starts to evolve.

The point I make to my clients is that this is natural human behaviour and should be supported and encouraged. That’s not to say the group of 15 you manage can’t be successful, you just need to communicate differently with them.

So if you’re ‘managing 15’ (or 10 or 20), I recommend you design your communication and team development work for how humans actually bond. Treat the 15 as a group, then build the teams inside it: create stable pods of 3–5, (they probably exist already as individual operational project teams). Give them permission to develop as their own team and work out their own cadence of catch-ups and ways of working. Then, make sure you also have a monthly 45-minute whole-group alignment i.e. share project updates and key learnings, and a quarterly 90-minute showcase of achievements with food/drinks (yes, this can be coordinated online too, with everyone bringing their own food to the call). This tops up the overall trust of your group and keeps the shared learnings flowing (the magic!).

Micro-pause exercises for each of your group’s ‘social circles’

So how can you act on this research and get each of your group’s social circles functioning as well as possible? Here are some ideas, drawn from our stable of micro-pauses for team development:

First, take a moment to identify your 5-15-50 at work. As we’ve established, this would typically be your “pod” team of 5 people or fewer, your wider operational group of around 15 people, and your department of around 50. Then,

Next: Put the following ways-of-working processes into action for each pod, operational group and department.

Your 5 or fewer: your pod

Micro-pause agenda (15 min):

1. 2 mins - check-in (your ‘story sharing’ with each other): “One thing you’ve learned this week.” More / better check-ins can be found here!

https://checkin.daresay.io/

1. 10 mins - unblocking each other: what I’m moving / where I’m stuck / one ask of each other.

2. 3 mins - sharing gratitude: one sentence appreciation of each other, to close.

Cadence: 15 minutes weekly (same people, same slot).

Why this works: Brief weekly synchronised touchpoints recruit the body’s endorphin bonding pathway, lowering stress and making psychological safety easier, helping blockers to surface early and enable decisions to speed up.

Your next 15 or so: your operational groups

Micro-pause agenda (45 min):

• 10 min – group check-in: In pairs: “What went well this month?” / “Who helped?” then share as a whole group.

• 20 min – decision snapshots for each pod team: Each pod shares what they’ve learned this month. For each: share the context, the key learning and why it’s important to share in this forum.

• 15 min – dependencies map: each pod team shares any blockers they need support with from the wider group.

• 5 min – Thanks + next: the group’s leader thanks everyone’s contribution and surfaces the agreed actions.

Cadence: 45 minutes monthly (every 4 weeks, fixed).

Why this works: A monthly rhythm avoids too many big and unwieldy meetings while still maintaining alignment on the overall goal and shared standards. Focusing on decisions and dependencies (not updates - they can be shared in the Teams or Slack channel) converts social trust into tangible alignment and, ultimately, less duplication and overlap.

Your next 50: your community

Micro-pause agenda (90 min):

• 20 min – story showcase: 3× 5-minute lightning talks from different pods; one learning each.

• 20 min – strategy (alignment around the shared goal): The department’s leader gives an update on progress for the quarter with Q&A.

• 10 min – recognition: Peer-nominated shout-outs (specific behaviours that relate to the organisation’s values or purpose / mission).

• 25 min – shared snack/meal: In-person if possible; if remote, maybe send a small treat voucher to redeem together, or if budget doesn’t allow for that then invite your participants to bring something to each / drink (and talk about!) on screen.

Cadence: 90 minutes quarterly (All-Hands + sociable element)

Why this works: A quarterly rhythm with story showcases to celebrate learning, plus a shared snack/meal. This delivers light, endorphin-friendly bonding at scale. Pride and belonging rise, good practice spreads, and teams feel more inclined to pull in the same direction.

Take away

You don’t need to fight against human nature anymore. Structure your communication and people development work for the 5/15/50 (and maybe 150) reality, and your ‘team of 15’ will start to function like Dunbar’s ‘sympathy group’ and really start to perform as a holistic, mutually supportive system.

References

• Dunbar, R.I.M. (1992). Neocortex size as a constraint on group size in primates. Journal of Human Evolution. ScienceDirect

• Dunbar, R.I.M. (2025). Why friendship and loneliness affect our health. Annals of the NY Academy of Sciences (review).

• Manninen, S. et al. (2017). Social laughter triggers endogenous opioid release. Journal of Neuroscience. Journal of Neuroscience

• Tarr, B. et al. (2015). Synchrony and exertion during dance raise pain threshold & bonding. Biology Letters. Royal Society Publishing

• Holt-Lunstad, J. et al. (2010). Social relationships and mortality risk (meta-analysis). PLoS Medicine. PMC

• Edmondson, A. (1999). Psychological safety and learning behavior in work teams. Administrative Science Quarterly.SAGE Journals