Sunday 6 June 2021
You hear some strange things on the radio in the middle of the night…

Somewhere between teacher assessed grades, mass testing and track n’ tracing, work stress has made the grim descent into insomnia. Although I invariably zonk out effectively enough in an exhausted heap; by around 2am I am awake again, tossing and turning fretfully in a fruitless quest to return to the illusive REM-cycle. When my mind is really racing, I switch the radio on, hoping for distraction, and this is where, a few nights ago…I discover the notion of numbers linked to social and workplace interaction. It is claimed that,
“You can only maintain so many close friendships“
The central name in the debate is evolutionary psychologist Robin Dunbar, best known for 150, his namesake ‘Dunbar’s number’. Dunbar claims that this is the number of ‘stable relationships ‘ we are able, cognitively to maintain at once. It is his ‘wider circle of friends’ number, the amount you’d expect to see at your wedding, or imagine at your funeral, as opposed to your closest most trusted companions. On the radio, the guest expert applies this number to the workplace too, as the number where you could know each colleague not only by name but also know something of them as a person: their role, their family, their interests, their ambitions. Its suggested that although variation is inevitable, this is a suitable number for that sense of unity and community that hallmark effective organisations. When employee numbers rise too far above this, our expert continues, some businesses choose to open a second office or warehouse to break the workforce down into more sociable sized units.
Now this draws me in because 150 is pretty close to the number of colleagues I work with and all of this is certainly true for us. Additionally too, it catches my imagination because, as a mathematician, I have a long standing fascination with the seemingly mystical existence of numbers and number patterns in society, in music, in art and in our natural world. Oh yes, our wonderful cardinals refuse simply to be confined to the dusty pages of some academic tome!
Hence, as this audio item moves onto explore other numbers, I find myself wide-awake. The theory examines various friendship thresholds. Five is the ballpark for close friends – shoulder to cry on friends, the ones who share your happiest (or saddest) news first friends. It is proposed that this is why we so often see quintets, or their near neighbours, winning appeal in popular culture; Enid Blyton’s Famous 5, ‘Friends‘, Scooby Doo‘s sleuthing squad and numerous rock and pop groups.
There is a long conversation about fifteen. In the relationship ranks, 15 is ‘best friends’ – around the number you’d have at a regular birthday meal, on a hen party weekend or those you’d call upon to look after your children. The radio discussion suggests that this stronger bond makes a suitable number for sporting teams and even expands to include Jesus and his disciples in the category.
From 15 they jump to 50 and then the renowned 150…

I lie there thinking it through for my life: reliving the times when friends did drop everything to support me and who they were, picturing the faces at my 30th Birthday Party or the various work teams I have contributed to and which worked well and which … less so. There or there abouts … those numbers work for me, although for a statistically minded soul, there is not a lot of space between 5 and 15 for variation! And I strongly suspect it was the clarity of definition of roles, rather than the size, that made several work teams successful or not. I imagine this could be an easy theory to challenge… from various directions.
Nonetheless, possibly akin to counting sheep, as I attempt to recall and count those who came to my Wedding I find myself drifting pleasantly off into a wonderful spell of sleep. I decide, whatever it limitations, that this is the theory for me after all…