This has been an aspect of human living and a leader’s lot for the duration of our history.
Clan
Apart from our family-sized group, there is a second group that gives us our sense of identity and which is critical to humans as social animals. This group is known as our clan and, in the natural course, comprises up to 150 people.
Social living was the key survival strategy for early humans. The savannah was a hostile and short-lived place for a solitary human or even a small lonely family. Compared to other animals on the plains of Africa also battling to survive, humans don’t have the same natural survival tools—we’re not strong like an elephant, we don’t run fast like a cheetah, we don’t fly like eagles or vultures, we don’t have sharp night vision like a cat and we’re not armed with poison like a scorpion. Our method of survival was social living—our families gathered in groups.
Group size is related to the size of the human brain. Our brain size allows us to associate with groups of up to around 150 others. Oxford professor Robin Dunbar is an expert on the topic. He argues that living in complex social groups demands a significant amount of intellect. Being a social animal, to get on you need to know who’s connected to whom, which family is not getting on so well with another, who is on the outer with the leaders and who recently won favours. This takes a fair amount of brain power. Dunbar has found a link between the ratio of brain to body size and the group size of animals (well, more accurately the ratio of the neocortex and body size). Humans have the biggest brain per body size of any animal on the planet. This larger brain allowed us to live in bigger groups than, say, chimpanzees, gorillas or monkeys. On Dunbar’s analysis the brain per body ratio of humans correlates to a community size of 150, which is indeed the size of primitive, or natural, human groups.
Chimpanzees are the second brainiest animals on the planet. They have the second largest brain per body size. On Dunbar’s analysis, chimpanzees would live in groups of around 55 on average in the wild, which is what happens. The main Gombe community, the Kasekela clan, numbers around 50 chimps.
For animals with a survival strategy based on family groups, there are great incentives for families to gather together. For starters, it’s the best defence against predation where bigger numbers can protect each other. There’s also attraction in sharing duties and sharing the search for food. In sourcing food, there’s a fair chance that if you miss out on finding food for a few days your family might not starve because another family will have enough to share, as yours did last time or might do next time.
The magical 150 appears in various places.
On Facebook the average number of friends in a network is 120.
For most people, if you take the time to list your friends and acquaintances your list will total around 150.
The ex-global CEO of Proctor & Gamble was personally involved in the career planning for a key group of 150 high potential people.
The prehistoric Tonga navy, a highly effective conquering force, built war canoes that were powered by 150 rowers.
If 150 is the number of people we naturally associate with, we have a fundamental challenge when our organisation grows beyond that size. Our brains are just not large enough for individuals to associate with and gain identity in organisations of 2,000, 20,000 or 200,000. Our brains are not big enough to manage the social and political complexities in groups significantly beyond 150. In larger organisations, then, people will naturally associate with their department, subsidiary or geography of a human scale of up to 150. ‘Silos’ will naturally occur in large organisations, so any search for an organisational structure that removes silos in large organisations will be rather fruitless (although senior leaders can mediate to reduce the natural sub-allegiances and selfish rivalry). The better organisational design question is to ask, ‘Where do we want the silos to form?’ Large organisations numbering way beyond the normal human number for connectedness will fracture into groups that individuals can most associate with.
The significance of 150 is further demonstrated by what repeatedly happens when small organisations grow towards that number. Consistently, people in organisations experiencing growth toward and beyond that threshold start to say, ‘It’s not as friendly as it used to be’, and, ‘We don’t know everyone like the old days’. Often in these smaller organisations the founders sense but don’t consciously realise the increased complexity that occurs when the organisation grows closer and then beyond the 150 mark. At this point the complexity is not linear—it’s exponential. When the organisation was 20 people then 30 then even 70 the founder knew each person well and was close to the job each person performed. As the organisation grows beyond 100 or so the founder can’t be across the level of detail that they used to be. They also start to rely, or should rely, on another level of management. Often the founder, not realising the significance of the growth, has not put in place the necessary processes, systems and capabilities to manage the growth in a sustainable way.
A significant implication of our clanning instinct is that we have an inherent fear of strangers. Over the millennia of our hardwiring circuitry, strangers mostly meant no good. More likely than not, they represented disputes over territory and competing claims over resources. In large organisations, colleagues outside our clan are like strangers. A ‘them and us’ occurs within the organisation, usually on geographical, functional or business unit lines.
Chimpanzees also display strong ‘them and us’ behaviours. At one point Dr Jane Goodall observed the Gombe community fracture into two groups, perhaps due to the increased population beyond the natural sized group. The smaller breakaway group took up occupation of a neighbouring territory. Competitive group rivalries boiled over into brutal warfare. Over the following two years, the main established group hunted down and killed all members of the splinter group. And these were individuals that up until recently had been part of their community.
While in organisational life our response might be more subtle, the intent is not such a long way from the Gombe chimp actions—we become protective of our in-group, we battle for resources, we talk disparagingly of the other department and conflicts can be more emotional with intra-organisation groups that we should by rights be friends with!
We will talk more about silos and the implications for leaders in the next chapter. At this point let’s look at the implications of the clan size of 150. I won’t go into as much detail as I did for the family-sized leader because the focus of this book is the role of the leader of immediate teams rather than leaders of the ‘village’ or the ‘tribe’.
The implications for leaders
First, the decision-makers in charge of organisational design should take into account natural clan formation in the structure of the organisation. We can create structures where the organisation uses group size advantageously. If we design our organisation according to human instincts we will harness natural energy. If we ignore human nature there’s a good chance we will design dysfunction into the system.
Gore Associates is the highly regarded firm and maker of GoreTex. Gore deliberately uses group sizes of 150. When Gore builds a new facility it provides car spaces for only 150 cars. When the car park starts to reach capacity, it’s time to build a new facility.
I referred earlier to Flight Centre. With its ‘family, village, tribe’ strategy, Flight Centre groups a certain number of family-sized stores or teams together in their geography so that there are around 80 to 100 people in a village. These village groups are encouraged to select nicknames for themselves, to create an identity, and the annual primary recognition awards go to a village group. Flight Centre in effect uses the clan-size concept to foster a healthy sense of rivalry rather than allow the rivalry to emerge in an unplanned and unmanageable way.
