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# Robin Dunbar | The Science of Friendship: Dunbar's Number and Social Circles
- URL: https://www.thebeyondpodcast.com/blog/robin-dunbar-the-science-of-friendship-dunbars-number-and-social-circles/
- Published: 2025-10-23T22:30:08.000Z
- Updated: 2026-07-29T14:27:04.000Z
- Description: Professor Robin Dunbar on the The BEYOND Podcast podcast: Discover the "cost" of friendships (200 hours), the importance of trust, the dark side of homophily, a
- Author: Elliott King
- Tags: insight

In this illuminating episode of **[Beyond with host Aleksandra King](https://thebeyondpodcast.com)** speaks with Professor **Robin Dunbar**, a renowned anthropologist and evolutionary psychologist, about the science behind our social lives. The conversation focuses on the definitive limits of human social networks, the structure of friendship, and the investment required to maintain lasting relationships.

### Unpacking Dunbar's Number: The Hard Limit on Friends

Professor **Dunbar** immediately addresses the most crucial question: What is the maximum number of friends and family one can maintain? The "official limit" is **150 people**, famously known as **Dunbar's number**.

This group encompasses all the individuals with whom you intentionally try to maintain contact at least once a year. Historically, this number aligns with those you would send a Christmas card to. **Dunbar** also notes that the average number of friends on Facebook is "actually **149**", reinforcing the validity of the number even in the digital age.

- **Acquaintances (≈ 500 people):** This is the next layer out, consisting of people you might "have a beer with after work but we would never invite them home".
- **Faces and Names (≈ 1,500 people):** The outermost layer includes people whose faces you can put names to , often public figures or celebrities. These relationships are typically "one way", you know them, but they do not know you.

![](https://storage.ghost.io/c/5e/74/5e74ba0c-c249-4586-8ce5-03deb56fdf93/content/images/2026/07/tbp-insight-1267745716.webp)

### The Intimacy Hierarchy: Layers of Closeness

Within the core 150 social network, friendships are structured into distinct layers defined by emotional closeness and frequency of contact.

| **Layer**                     | **Number of People** | **Description & Contact Frequency**                                                                              |
| ----------------------------- | -------------------- | ---------------------------------------------------------------------------------------------------------------- |
| Inner Core                    | 5                    | The "shoulders to cry on" friends; your primary support group. You generally see them at least once a week.      |
| Sympathy Group                | 15                   | The group you would be "genuinely upset about" if they died. This is your regular social "clique".               |
| "Barbecue" Friends            | 50                   | The circle you would invite to a larger party or summer barbecue.                                                |
| Weddings and Funeral Invitees | 150                  | The full extended network, including family up to second cousins, who attend "bigger once in a lifetime events". |

Professor Dunbar highlights that these numbers are "spookishly accurate". He also explains that there is a range of variation for the 150-layer, from about 100 for introverts to around 250 for extroverts.

![](https://storage.ghost.io/c/5e/74/5e74ba0c-c249-4586-8ce5-03deb56fdf93/content/images/2026/07/tbp-insight-2174713741.webp)

### Key Takeaways

1. **Dunbar's Number is 150:** This is the cognitive limit for meaningful social relationships you can maintain.
2. **Layers of Intimacy Matter:** Relationships are tiered, with only 5 people forming the deepest, most frequently contacted core.
3. **Family is Defined by Kinship:** All genuine biological family are typically contained within the 150-layer, extending only to about second cousins.

![](https://storage.ghost.io/c/5e/74/5e74ba0c-c249-4586-8ce5-03deb56fdf93/content/images/2026/07/tbp-insight-641499620.webp)

You can listen to the full episode on the [Aleksandra King YouTube Channel](https://www.youtube.com/watch?v=o6kAMueyyfI) or read more on [the dynamics of social life and mechanisms of social bonding.](https://thebeyondpodcast.com/blog/robin-dunbar-on-the-cost-of-friendship-gossip-and-the-jane-austen-problem)