Is the optimal number of friends you need to have 150?

The optimal number of friendships in our lives is 150, says evolutionary psychologist and mathematician prof. Robin Dunbar. He developed his concept, among others, in the book "How many friends does a person need?" We can maintain so many relationships, intimate, close and somewhat distant, and this number also includes family members. 150 is "Dunbar's number". According to the professor, family is simply a "special kind of friends". “We have family first, and then if we have spaces left, we fill them with friends and acquaintances to whom we are not related. Friendship in this sense is a relatively new phenomenon, a consequence of the dramatic decline in family size in Europe and North America over the last two centuries," wrote Prof. Dunbar.

What types of friends are there?

In such a large group, the types of bonds and relationships we have with each person obviously vary. Aristotle already distinguished three types of friendship:

• those that we today call "useful" or "business",
• those for pleasure,
• true, deep friendships based on deep feelings.

There are usually 5 people in the closest circle, and a little further away - still close - 12-15 people. We see about 50 people once a year. The rest are just friends we meet occasionally.

As we age, we have fewer and fewer friends.

As it turns out, the older we get, the narrower our circle of friends becomes ¹ . Moreover, according to a study that lasted over 30 years and was aimed at assessing life satisfaction in the context of relationships, we are happiest if in the third decade of life we ​​focus on the number of friends and acquaintances, and in the fourth decade we make the quality of relationships a priority. .

Was Dunbar wrong about the optimal number of friends?

However, new research conducted by scientists from the University of Stockholm provides different information. According to researchers' findings, the number of acquaintances that is optimal is significantly different from Dunbar's number. Prof. Dunbar conducted his research based on observations of groups of primates (monkeys). Meanwhile, Andreas Wartel, co-author of the Swedish study, believes that "it is impossible to determine the average for people based on available methods and data" ² .

Researchers claim that Dunbar's number was based on the assumption that the volume of the cerebral cortex in primate brains determines the size of the social groups they can form. Now scientists, using statistical techniques and advanced methodology, believe that the number of 150 is significantly overestimated. According to them, a person is able to maintain and cultivate from 69 to 109 friendships ³ . They also indicate that there are fundamental differences in the structure of the brains of monkeys and humans and in the ability to create social structures. Therefore, the way primates create and nurture bonds cannot be translated to humans one-to-one.

How many close friends do we need?

The optimal number of close friends is between 3 and 5 people - that's how many really close relationships we can maintain, which require time and emotional involvement. ⁴ . And this number is absolutely enough to feel greater satisfaction with life and derive health benefits from friendship, which you can read about here.

Bibliography:

1. Carmichael, C. L., Reis, H. T., & Duberstein, P. R. (2015). In your 20s it's quantity, in your 30s it's quality: The prognostic value of social activity across 30 years of adulthood. Psychology and Aging, 30(1), 95–105.
2. “New study deconstructs Dunbar's number – yes, you can have more than 150 friends”, Stockholm University Communications Office, su.se, May 5, 2021.
3. Lindenfors P, Wartel A, Lind J. 'Dunbar's number' deconstructed. Biol Lett. 2021 May;17(5):20210158.
4. Suzanne Degges-White, “How Many Friends Do You Really Need in Adulthood?”, Psychology Today, August 9, 2019