Just this weekend I visited a newly built high school. The school was designed with a specific guideline, based on an old saying amongst teachers ” if you hear a name mentioned of a pupil and you have no idea who it is, the school is too big”. So the architect and the management divided the space into seperate area’s (age groups and education) no bigger than 200 students. Teachers and students “live” within this area most of the time and get to know each other by name and face. Great idea !
In the last million years, as our brains grew explosively – as one scientist put it, “perhaps the most improbable event in all of evolution, anywhere” – much of the potential of all that new gray matter was put to work for social benefit. The “new brain” or neocortex, which is the most dramatically enlarged portion of the human brain, seems to be the area dedicated to our social relationships.
We know this because, in 1992, British anthropologist Robin Dunbar compared the average troop size of gorillas and chimpanzees against the average tribe sizes of humans. He found that there was a direct correlation between the volume of the neocortex in these three species and their average troop or tribe size. This value, known as “Dunbar’s Number“, is roughly 20 for gorillas, who have the smallest neocortex, about 35 for chimpanzees, and – for us lucky human beings, who have the greatest selection pressures on our social behavior – just under one hundred and fifty. We may not be entirely exceptional, but we’re doing quite well.
Essentially, inside of each one of our heads, there are a hundred and fifty other people running around. Yes, that sounds a bit crowded (particularly when they’re up partying all night long with their mates), but it’s actually imminently practical. These “little people” inside our heads are models of each person we know well: our family, our friends, our colleagues. For each of these people we build mental model which helps us to predict their behavior. (It isn’t really them, but rather, our image of them.) This predictive capability smoothes our social interactions. We know how to interact with people whom we have in our heads; with others we remain demure, reserved – in a word, predictable. Only with intimacy do we express the quirks of behavior which make us unique, only with intimacy do we take note of them in others.
