Doctor SpinMedia & PsychologyBehavioral PsychologyGroup Sizes (from Support Cliques to Tribes)

Group Sizes (from Support Cliques to Tribes)

The science of in-groups in a wired world.

Humans tend to organise themselves in stable group sizes.

The most famous group size is probably Dunbar’s number.

150—Dunbar’s Number

Most of you know Dunbar’s Number. It’s based on the idea that every one of us has limited social bandwidth.

“Dunbar’s number is a suggested cognitive limit to the number of people with whom one can maintain stable social relationships. […] No precise value has been proposed for Dunbar’s number. It has been proposed to lie between 100 and 230, with a commonly used value of 150. Dunbar’s number states the number of people one knows and keeps social contact with, and it does not include the number of people known personally with a ceased social relationship, nor people just generally known with a lack of persistent social relationship, a number which might be much higher and likely depends on long-term memory size.”

Source: Wikipedia

Learn more about Dunbar’s number.

But there are other notable group sizes apart from Dunbar’s number. These stable group sizes range from support cliques (3-5 people) all the way up to tribes (1,000-2,000 people).

Group sizes in social media

There seems to be some order in the complex chaos of human relationships:

Support clique (3-5 people)
Sympathy group (12-20 people)
Band (30-50 people)
Clan (150 people)
Megaband (500 people)
Tribe (1,000-2,000 people)

It’s basically the science of in-groups in a wired world.

As we entered into an industrial society, physical group sizes decreased. A theoretical assumption is therefore that the digital landscape has enabled us to reclaim some of these group sizes. One such effect is that the internet allows us to find many different types of tribes and many different types of people to “include” in our groups.

In public relations, what used to be dictated by physical proximity, is now completely rid of any such restrictions.

Today, we live in a wired world where you can maintain meaningful relationships with individuals to whom you have no geographical connection. Still, you might know exactly what they had for breakfast this morning.

But while online influence is social by nature, it still isn’t evenly distributed: Through the power of technology, influencers and celebrities tend to have been made part of many people’s social in-groups and this is, of course, a massive volume of one-sided relationships.

The counter-balance to the one-sidedness of widespread influencer- and celebrity worship is that we, the audience, can make ourselves part of many different types of in-groups based on identities and roles we choose for ourselves.

Identities and Roles in a Networked World

I would say I do know 150 people that I’ve spent time with over the years.

But I also know 150 colleagues that I’ve had. I would also say I know 150 people from the public relations industry, for sure. And I know at least 150 social media naturals, and so on.

How does this scale social media marketing?

I appreciate this model by Viil Lid, PhD candidate in Communication & Information Sciences at the University of Hawaii:

How to scale social media marketing.
The Interest Group Model: How we as individual shift between roles and communities.

When I’m asked what makes the “social media revolution” so special, I always say that never before in human history have we seen human groups forming at such speeds, almost totally independent of demographic factors.

It’s the amplification of Dunbar’s number at interest group level — not due to any sudden increase in our capability to sustain more than 150 relationships.

Group sizes of sustainable relationships

What makes the effects of digital spread show likeness to viral infections are the fact that there are boundary spanners, individual nodes that has existing relationships in several different types of interest networks.

For each of these networks, Liid once again shows us a model that I’ve been using on several of the seminars I’ve given:

Group Sizes | Behavioral Psychology | Doctor Spin
The Social Layers Model: We are able to sustain larger networks as ties go weaker.

How many “Dunbar number interest tribes” can a single individual sustain?

If we dig deeper into this question, we must also determine the strength of the bindings between individuals. Interestingly enough, we see Dunbar’s number in action once again:

Inner core (3-5 people)
Semi-private layer (<150 people)
Superficial layer (>150 people)

How social media scales in a networked world

To build trust is a journey from the periphery to the centre. You start any relationship, whether with an individual or a brand, by being a stranger.

PR professionals should explore the digital space; not for clicks, memes, or virals, but to build and maintain relationships using online social psychology.

Not every stranger becomes a friend and the deeper the relationship, the bigger the gravitational effort is required.

If you’re creating a campaign, it’s important to cater to the inner circles for sure, but don’t forget the outer circles.

Social media doesn’t scale linearly, but tapping into several different and pre-existing interest groups does (see also The Engagement Pyramid).

Also, social media sharing is dependent not primarily on volume exposure, but on niches social sharing incentives (see also The Secret Sauce for Social Media Sharing).

What you should expect from an individual depends primarily on their situational context and communicative behaviour, as in publics, not their demographic characteristics.

Cover photo by Jerry Silfwer (Prints/Instagram)


Jerry Silfwer
Jerry Silfwer
Jerry Silfwer, aka Doctor Spin, is an awarded senior adviser specialising in public relations and digital strategy. Currently CEO at KIX Index and Spin Factory. Before that, he worked at Kaufmann, Whispr Group, Springtime PR, and Spotlight PR. Based in Stockholm, Sweden.
Buy PR Merch

Grab a free subscription before you go.

Get notified of new blog posts & new PR courses

🔒 Please read my integrity- and cookie policy.

Social media companies like Google and Facebook are powerful, but that doesn't make them evil. Paradoxically, they're too good for us to handle.
Most popular