Mental Illness, Dunbar’s Number, and the Divine Right of Kings

“I thought I alone considered your boyfriend a narcissistic moron, but the whole galaxy does.” – Hitchhikers Guide to the Galaxy

DSC03743

The Tribe begins its annual war, an ancient rite known as “dodge ball.” 

What if we’ve been looking at mental health . . . all wrong?  This may be the most interesting thing you read all month, maybe all year.  But that’s just what a narcissist would say . . .

I was thinking the other day (a dangerous thing to do, I know, thinking is something to be left to those that work at universities and in congress) and had an idea.  Maybe (some) mental illness has a purpose.  I’ll explain, but first I have to explain Dunbar’s Number, which, of course, is named after Kim Kardashian.  I’m kidding.  Dunbar’s Number is named after Caitlyn Jenner.

Robin Dunbar, British Psychologist, looked over the size of the human neocortex (not Neo-Cortez, who would take over the Neo-Aztec) and after playing with a particularly plump and pleasant neocortex, decided that brains just might have something to do with how humans relate to each other.  The neocortex is actually the newest (in a biological sense) portion of the brain, and allows humans to do complex things, like talking, snorkeling, and making microwave ramen.

Dunbar looked at primate group brain sizes, and compared to the size of the neocortex to the size of the primate “group” or tribe.  After running the math, he predicted that humans should have a group size of around 150 – it’s related to the size of working memory that you have about other people.  The commonly accepted maximum stable group size (average) is 100-250, which explains why I need to have my children program the streaming box hooked up to my television – my working memory is full of details like the shoe preferences of the administrative assistant at work from six jobs ago.

Dunbar further theorized that larger groups could only stick together under strong survival pressures – you’d have to be pressed to work together by a fate as tough as death.  Why?  Because people are tough to deal with.  And it takes time to deal with people, rather than strangle them.

One potential reason that the “Dunbar” number for people could be higher than predicted is language.  Whereas other primates have to use non-verbal cues like body-slamming them, people, after the advent of language, can talk to each other so they can explain why they are body-slamming you.  For that reason, especially when dealing with modern (the last 12,000 years or so) humans, I favor a Dunbar number in the 250 range.

There is some validity to the number.  Anecdotally, I’ve been involved with a company that had two divisions in the same area.  One had 120 or so employees.  The other?  It had far greater than 500 employees.  I observed that the smaller division operated as a single unit.  Every employee knew every other employee – and they knew about their families, their hobbies, and their history.  Did that consume time?  Sure.  You couldn’t just go over to talk with one of them – the entire social greeting took at least 10 minutes.  You had to catch up.  And that’s the way that close relationships work – you can’t just say “hi” and walk on, you have to catch up with each other.  That explains why when I come home, The Mrs. wants to talk and stuff.  We’re engaging in a practice that’s at least thousands of years old.

The larger division had broken up into various factions based on job functions.  These factions looked like little tribes – each had a leader, an agenda, and they fought against each other regularly, often over nothing.  And each of these fights ended up hurting the company.  Gore-Tex® found the same thing – they built buildings for 150 people.  When the building filled up?  They built a new one.  They tried to keep the trust, the positive aspects of the tribes predicted by Dunbar from spilling over into intertribal warfare that happens at larger group sizes.

But ancient tribes didn’t have kid’s soccer, and FaceBorg®, and the myriad of connections that occur outside of work.  So, the Gore-Tex™ number is smaller than the “actual” tribe size.  Again, 250 seems about right.

So what does this have to do with mental illness?

Well, for a tribe to survive over time, while most members would be able to act as general “tribal” members most of the time (i.e., hunting, gathering) there would also be the need for specialist skills and attributes.  Situations the tribe might encounter (and overall group cohesiveness) require different talents.

Let’s take schizophrenia.  It’s prevalent in about 0.4% of the population.  It often manifests with being able to hear things that aren’t there, see things that don’t exist, and believe in a reality that others can’t see.

Sounds like a Shaman to me.  Every good tribe needs one, right?  Well, 0.4% is 1 person out of 250.  I got goosebumps when I did that calculation – the number seemed like a nice fit for the theory right off the bat.

Okay, what about another common mental condition?  Anxiety.  Anxiety is found in about 10.6% of the population.  So, in our tribe of about 250 we’d have about 26 planners.  26 people worrying on a daily basis about how the whole tribe would die.  These people are a pain in the butt, but this ability to dream up a constant set of disasters that the tribe could anticipate and avoid has huge survival value.  In today’s world, not so much.  Back 8,000 years ago?  This was an amazingly important skill.

About 6 of our 250 tribe would be obsessive-compulsive.  Mainly older folks.  I can see the meticulousness compulsion of the older, wiser tribal member being infectious – and leading to greater spread of learning throughout the tribe.  There are certain things you have to do right, you have to double check (think food poisoning) or else the tribe will die.  Having these super process-driven people might have been quite a help.

About 6 would of the tribe would be paranoid.  Again, like planning, it serves a purpose – but in this case the paranoia is about what other groups are doing and thinking.  Very helpful to have someone looking for the hints that the tribe will be attacked from outside.  Or, from inside.  Are you threatening me?

Narcissism?   About 1%.  Only so much room for leaders.  This would have about 2 of them in the tribe.

Psychopath/Sociopath?  About 1.2%.  So, 3 bold, direct, mean leaders of raiding parties/war parties.  It takes a village to kill another village.

kermit direction

Pictured:  Psychopath.  I like the cut of his jib! 

Outside of oral history, our hypothetical tribe had only one way to pass on information about required roles and how to do them – genetics.  Genetics matter – many of these conditions are at least partially inherited, making it more likely that the leader was . . . the son of the leader.  The shaman was . . . the son or daughter of the last shaman.

This genetic tendency to replace the leader with the leader is (likely) the source of the concept of hereditary royalty and hereditary nobility.  And, genetically, those people were likely the best leaders around at that time, and they kept breeding . . . so, there was (at least for a while) some good reason to think that the Hohenzollerns and Hapsburgs might be pretty good choices for kings.  They were bred to be kings.  Now:  perhaps a bit too much cousin-lovin’ (LINK)?

So, yeah, all of the roles required for a self-sufficient band are built within our genetic profiles – but some of them aren’t valued so much in our current society – we don’t need a half-dozen war-band leaders in every high school.  And, as far as I know, this is an idea I developed (more or less) independently.    Which is also something a narcissist would say . . . hmmm.

Author: John

Nobel-Prize Winning, MacArthur Genius Grant Near Recipient writing to you regularly about Fitness, Wealth, and Wisdom - How to be happy and how to be healthy. Oh, and rich.