BPP Blog

Those who have encountered, in whatever medium, The Hitchhiker’s Guide to the Galaxy will know that the answer to ‘life, the universe and everything’ is exactly 42. However, it looks like this answer needs to be qualified and, as far as some human organisations are concerned, the number is, in fact, around 150.

It seems that ‘groups’ do have natural sizes, grounded on our biology, depending on what they are for. 150 is Dunbar’s number. (“How Many Friends Does One Person Need? Dunbar’s Number and other Evolutionary Quirks”, Faber and Faber, 2010)  Robin Dunbar, an anthropologist who believe his  research on apes has implications for people,  has concluded that the number of people we can maintain a close social relationship with, where group survival is at stake is 150; 150 is the likely size of a tribe of hunter gatherers;  150 is the size of the average business unit at the makers of Gore-Tex; in the army, 150 is the size of a ‘company’ in a battalion, and it is the ‘company’, not the battalion,  which excites the greatest personal loyalty. (Nothing new in this: read the Iliad.) They key is that people are able to keep tabs on each other, and enforce group norms by peer pressure, culture and so on.

Survival is the incentive that brings these groups of this size together, but there is a huge amount of cognitive effort involved in keeping up to speed with this many people. Where survival is not at stake, there is less reason to spend so much time tab-keeping, and  the ‘natural’ group size may be smaller. (Read Christopher Allen’s post on lifewithalacrity.com:…he has hypothesized that the optimal size for active group members for creative and technical groups  hovers somewhere between 25-80.) The size of the College of Cardinals of the Roman Catholic Church (the world’s oldest organisation) hovered for centuries between 40 and 50, and is now about 175.

Once groups reach a certain size, they cease to function well, everyone gets hacked off keeping things together, an.  In fact, as we increase group sizes beyond 80, to 150, 200, or even 350-500, we break them up into smaller ones so “they can be understood and managed by people — and so efficiency reasserts itself”. Dunbar says that ‘A rule of thumb commonly used in business theory is that organisations of fewer than 150 people work fine on a person-to-person basis, but once they grow larger, they need formal hierarchy [and departmentation[ to be managed efficiently”.

Like us, many apes are highly social - baboons for example have an instinct for the minutiae of social status as finely honed as that of the seat-planners at the recent Royal Wedding.  And they spend ages grooming each other, as this is a mark of status and attention, making sure they are all on the same page. (Bonobo apes take this to extreme: delicacy forbids detail, but the well-wined aftermath of an academic conference should give you the general idea. )

So, has technology wrought a fundamental change in how we engage cognitively with other people?   Group cohesion is certainly easier for humans than it is for the intensely social apes. Language is perhaps the first ‘technology’: with language, we can create communities out of thin air, spin out memories, create culture.  (A nation-state was once described as an ‘imagined community’. Language was used for nation building in the last two centuries, and still is.)

But now we have the Internet and social media. With the former, we can join forces with conspiracy theory obsessives the world over – or, positively, communities of practice, professional specialists, other people with similar life issues. With the latter, we can vastly expand the number of contacts , and contacts of contacts, and friends we can engage with? I now find myself one degree of separation from the Pope.  Go on to facebook and linkedin and you will see people with enormous communities of friends and contacts.

So, will Dunbar’s number be seen, just like ‘42’, to be a good try? Are we suddenly becoming a sort of hive-mind?

Well, even in this environment, where relationship networks suddenly become visible (not least to advertisers), Dunbar’s number, he says, still appears to hold. Firstly, most people ‘have an average number of friends’, with a handful over 200. Furthermore, what really counts as a friend? Those with large numbers of ‘friends’ often know little or nothing about most of the individuals on the list.

So, as this is a serious blog,  I’ll give you some homework. A donation of [£150 – up to group marketing to decide] to a charity of your choice to  the person who can  write the best 150 words on each of the questions below. [closing date? Also legal compliance on ‘competitions’ and promotions etc]

1. Should 150 be the maximum business unit size? And how?
2. Retrieving your inner ape: how much of your business meetings, strategy days, performance reviews, communications are really about ritual social grooming than actual content?
3. Are social media more about ‘personal branding’ and status than friendship?
4. Survival is a great incentive for large numbers of people to work together. What does this mean for teambuilding and motivation?