First of all, Professor, the obvious question, how did you arrive at the number 150?
By prediction from an equation relating group size to brain size in monkeys and apes. It is all the people you know and have relationships with, so including family as well as friends.
This number is interesting. When we go through the process of developing ‘friends’ on the social network and friends of friends, this exercise would appear to be quite meaningless. Do these friends even faintly know who we are?
Even on Facebook, most people only have around 15-250 “friends”, which would be typical of this age group even in real life (face-to-face friends). Facebook encourages you to befriend friends of friends, and some people do. In this, they are behaving just as they do in the face-to-face world, where we would call these people acquaintances – they would create a circle of about 350 other individuals beyond our conventional 150 friendship circle). But these are not friends in any real sense, just people we know vaguely. And so many people decline to befriend them, or maybe befriend them and then quite soon afterwards unfriend them!
How does this number of 150 relate to celebrities, whether they are on the social network or not?
They still have this number of friends in real life, although remember that in real life this number is only an average and the variation round it is roughly 100-250. So celebrities may be the kind of people who can manage more friends, and be at the top end (around 200-250). What they have as followers on Facebook or twitter is irrelevant: they don’t know most of these people. A Swedish TV chat show host went to visit everyone (several thousands) on his Facebook page a couple of years ago to check out whether I was right. He decided I was right!
Does this number of 150 also apply to those living in close knit communities in places like Italy, or many countries in Latin America and Asia?
Yes. Usually in these old communities, the community is around 100-200 in size, so that everyone’s 150 is the same as everyone else’s in the village (everyone knows everyone – but of course they have different grandmothers, who are sisters or cousins!). This makes the community very close and supportive, much more supportive than more dispersed communities in cities where many people in the same street are strangers.
According to you, Professor, would you say there can be a negative impact associated with developing or trying do develop social contacts beyond a certain approximate number?
Creating friendships costs a lot of time. How willing someone is to help you depends on how warm your friendship is, and this depends on how much time you spend with them. If you divide your limited time among many people, you will have weaker relationships. This is the difference we see between extroverts (who have many weak friendships) and introverts (who have fewer, stronger friendships).
As a professor in a renowned educational institution, how many social contacts would you estimate that you have?
I have never counted them! You should never study yourself.
Please tell us a little about your background?
Originally I studied the behavior of monkeys and antelopes, and then about 20 years ago switched to study humans. My main interest is social evolution – how societies evolve in animals and humans.
Please also tell us about your growing up, who and what motivated you towards your academic interests.
I grew up in Tanganyika, in East Africa. When I went to University, I was interested only in Philosophy, but because I did a degree in Philosophy and Psychology I became interested in the study of behavior. So I did my PhD studying the behavior of baboons in Africa.
Our readers look up to the educated elite, of course. What would be your advice to our readers, who are mainly young adults in different parts of the world?
Friendship is the most important thing in life: it has more effect on your happiness, health and how long you live than anything else – including all the medicines, exercise and anything else.