Friends Are At The Core

It appears that friends and social networks are much more important to human’s overall mental and physical health than one might think.  A recent review published by Dunbar (2018) looked at how friendship affects humans as well other animals. Dunbar (2018) does a good job of connecting our history as humans including when we lived in hunter and gatherer communities as well as the most recent developments in the area of friendship in the last few decades.

Friends, not only make us feel happier about ourselves and our lives, but they can also shield us from mental and physical ailments, as well as allow us to heal faster from a sickness or surgery (1-11).  Friendship affects our health, happiness, and well-being more than any other single variable in our lives.  This may appear obvious, but it’s still quite undervalued, I would say, in modern life.  Friends are defined as people that we want to keep connections with as well as feel emotionally bonded instead of just people or strangers that we meet casually (12).  Friends include our romantic partner as well as family extensions in addition to the more commonly thought of friends, which are people that one is not related to biologically (12).  This is not to say that your romantic partner is the same value to you as a regular friend.  Researchers have actually created a different tier system for our social networks (13), but I will go into that shortly.

Friends also have a potent positive effect on our ability to fight off disease as well as lowering the risk of dying from a disease, only second to quitting smoking (14).  This relationship between friends and better mental and physical health is not limited to our species, it also includes other animals such as baboons.  It appears that female baboons which have a larger number of friends, also referred to as grooming partners, display lower cortisol levels (a main hormone related to stress) (15, 16), have larger numbers of children, and live longer lives (17-19).

Interestingly, there appears to be a limit to the total number of people that one can have in the broad sense of a friend, with the average number of individual’s social network being around 150.  This includes people we meet in person (20, 21), we call on the telephone (22), and who we communicate with on the internet (23-25).  It is noteworthy to mention that this number is very often found in different societal organizations of humans, such as communities of hunters and gathers as well as many small village sizes throughout history (26). This number of 150 is inclusive of all our commonly thought of friends as well as all of our family extensions and is common through cultures and populations, however there is a large variance which is around 100-250 people (20, 26).  There are obvious differences in people’s personalities as well as life strategies that may account for this (12), but it is still an unusually large variance.

This number of 150 is talking about the amount of people that we can be friends with, because after this number, or somewhere around this number, up to 500 are considered acquaintances.  Out of the 150 people in our social networks, there is a common tier structure like I talked about earlier made by researchers (13).  These are approximations, of course, but the tiers, which also represent number of people are:

  • 5 = main partners in one’s life
  • 5 = friends on a more intimate level (including extended family members as well)
  • 15 = best friends
  • 50 = good friends
  • 150 = friends (12)

One can alternatively think about this as:

  • The 1.5 tier is the main romantic partner or partners (12)
  • the 5 tier as people that support you emotionally and has been referred to as the “support network” (13)
  • the 15 tier can also be referred to as people that you are regularly social with (and possibly take care of each other’s children) (27)
  • the 50 tier as the “social party” people that you know (27)
  • the 150 tier as different people or groups that you may modestly gain as well as give information and support to (27)

In addition, there are two more tiers which can be understood as:

  • the 500 tier for people that you are acquaintances with
  • the 1500 tier which is believed to possibly be the maximum number of faces that we can connect to people, but it’s not tested yet (12)

Interestingly, these tiers are similar to hunter and gatherer organizations (28, 29), as well as modern armies (30). Additionally, other social animals, such as chimpanzees, baboons, elephants, and dolphins have the same tiers and ratios (31).

I believe that these findings are further evidence that we are not always living the way we were designed to live and function optimally.  Today, I believe that the grand majority of people in cities and different societies live and work in a manner that does not nurture social relations and friendships.  Does the constantly increasing number of hours workweek support or fulfil our most basic needs of community, caring, and love that we so desperately need and desire? One’s life options, definitely, depend on how much money one makes, how many people one or two parents must provide for if children or other dependents are in the picture, as well as many other situations and circumstances but there are many alternate ways of living and lifestyles that can support such a reality of valuing social relations and friendships.  

I feel that, all too often, people replace the support system of people in their lives with their job or other means of making money in hopes of feeling a sense of security.  Of course, we all need to work in order to live and function in society.  I personally believe, as well as many others, however, that humans are working the longest workweeks we have in a long time in history, possibly ever, especially in the US.  This time restriction has obvious ramifications for our social networks.  It feels as though, at times, that humans in modern society tend to look at friends as a luxury, if we have time for it after our responsibilities.  We rarely seem to see friends and community as a basic fundamental part of our existence.  One can be with friends when we are done with work or school, if it’s convenient, but often friends and the extended social network are not seen as a necessity to life, just extras to the few most important people in one’s life. Does this sound familiar?  This potentially gives another reason as to why there is such a large variance of the average social network number of 150.  I’m not trying to tell anyone how to live and I never will.  I simply believe that there is irrefutable evidence to the fact that we, humans, are an extremely social animal and benefit immensely from friends in many aspects of our lives.  The good news is that we can reap the rewards by prioritizing friendships in our lives!






This post has summarized some findings from a review:

Dunbar, R. I. M. (2018). The Anatomy of Friendship. Trends in cognitive sciences, 22(1), 32-51.

Findings from different studies within the review that are used in this post are cited in the references (they are in the order in which they are presented in the post, with number 12 corresponding to the main review article listed above)



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