Social Group Sizes (The Social brain Hypothesis)

Humans tend to organ­ise them­selves in stable group sizes.

What used to be dic­tated by phys­ic­al prox­im­ity is now com­pletely rid of any such restrictions. 

The inter­net allows us to find many dif­fer­ent types of tribes and many dif­fer­ent types of people to “include” in our groups.

Today, we live in a wired world where you can main­tain mean­ing­ful rela­tion­ships with indi­vidu­als without geo­graph­ic­al con­nec­tions. But how large can such groups be?

Let’s take a closer look:

Dunbar’s Number

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

Read also: Group Sizes (From Support Cliques to Tribes)

From Support Cliques to Tribes

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

Typical Social Group Sizes

Have you ever heard of the social brain hypo­thes­is? ¹Zhou WX, Sornette D, Hill RA, Dunbar RI. Discrete hier­arch­ic­al organ­iz­a­tion of social group sizes. Proc Biol Sci. 2005 Feb 22;272(1561):439 – 44. doi: 10.1098/rspb.2004.2970. PMID: 15734699; PMCID: … Continue read­ing

“The ‘social brain hypo­thes­is’ for the evol­u­tion of large brains in prim­ates has led to evid­ence for the coe­volu­tion of neo­cor­tic­al size and social group sizes, sug­gest­ing that there is a cog­nit­ive con­straint on group size that depends, in some way, on the volume of neur­al mater­i­al avail­able for pro­cessing and syn­thes­iz­ing inform­a­tion on social rela­tion­ships.“
Source: Discrete Hierarchical Organization of Social Group Sizes

Scientific evid­ence sug­gests that people tend to organ­ise them­selves not in an even dis­tri­bu­tion of group sizes but in dis­crete hier­arch­ic­al social groups of more par­tic­u­lar sizes:

Alas, there seems to be a dis­crete stat­ist­ic­al 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)

“Such dis­crete scale invari­ance could be related to that iden­ti­fied in sig­na­tures of herd­ing beha­viour in fin­an­cial mar­kets and might reflect a hier­arch­ic­al pro­cessing of social near­ness by human brains.“
Source: Discrete Hierarchical Organization of Social Group Sizes

Read also: Group Sizes (From Support Cliques to Tribes)

💡 Subscribe and get a free ebook on how to get bet­ter PR ideas!

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

Online Identities and Interest Groups 

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 also know 150 people from the pub­lic rela­tions industry, for sure. And I know at least 150 social media nat­ur­als, and so on. 

How does group form­a­tion scale in social media? 

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

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 inde­pend­ent of demo­graph­ic factors. 

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

Group Sizes of Sustainable Relationships

The effects of digit­al spread are likened to vir­al infec­tions because bound­ary span­ners and indi­vidu­al nodes have 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 in sev­er­al of the sem­inars I’ve given:

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

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

The Engagement Pyramid

Building trust is a jour­ney from the peri­phery to the centre. You start any rela­tion­ship 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. Social media does­n’t scale lin­early, but tap­ping into dif­fer­ent and pre-exist­ing interest groups does.

When cre­at­ing a cam­paign, it’s essen­tial to cater to the inner circles, but don’t for­get the dif­fer­ent lay­ers of the engage­ment pyramid. 

The Engagement Pyramid

The 1% rule of online engage­ment was mainly an urb­an legend on the inter­net. Still, a peer-reviewed paper from 2014 entitled The 1% Rule in Four Digital Health Social Networks: An Observational Study con­firmed the 1% rule of thumb.

Active pub­lics dis­trib­ute them­selves in a way proven sci­en­tific­ally by soci­olo­gists — long before the inter­net and social media emerged. 

The engage­ment pyr­am­id divides pub­lics into three dis­tinct groups:

• Creators (1%)
• Contributors (9%)
• Lurkers (90%)

When study­ing inter­net for­ums spe­cific­ally, it’s not uncom­mon to find that 90% of users have nev­er pos­ted (lurk­ers), 9% are adding only to exist­ing top­ics and threads (con­trib­ut­ors), and 1% are act­ively start­ing new sub­jects and threads (cre­at­ors).

The engage­ment pyr­am­id is some­times called the 1% rule or the 1−9−90 rule.

Read also: The Engagement Pyramid

💡 Subscribe and get a free ebook on how to get bet­ter PR ideas!