Do Dogs Count Toward Dunbar’s Number? Notes on Social Bandwidth

 1. Dunbar’s Number as a Cognitive Budget

Robin Dunbar proposed ~150 as the upper bound of stable human relationships. The “budget” is not strict but reflects the cognitive and emotional effort needed to track reciprocal ties.

2. Should Dogs (or Pets) Count?

• No, from a strict anthropological perspective: Dunbar derived the number from primate grooming networks.
• Yes, from a psychological bandwidth perspective: if a dog occupies emotional and cognitive attention, it displaces human slots.
• Practically, pets (including "man's best friend") show up in the innermost rings (the “support clique” of ~5), reducing available room for people rather than expanding the outer layers.

3. Variation and Standard Deviation

The mean (average) is ~150, but the distribution matters.

• Range: 100–250, with a standard deviation ~30.
• Gender:
• Women: do women have fewer but deeper ties, especially in the inner circles?
• Men: do men have broader but looser ties, especially in outer rings?
• Personality:
• Extraverts: more total ties (+20–30), especially in outer rings.
• Introverts: fewer total ties, but stronger investment in the core.
• Generational:
• Boomers / Gen X: denser, smaller webs (family, community).
• Millennials / Gen Z / Gen Alpha: wider apparent networks (social media), but the stable core remains unchanged.

4. Implications

• Dunbar’s number is elastic but not infinite.
• Emotional “bandwidth” is shared between humans, pets, and possibly: named objects ("Betsy", the temperamental truck), AI companions (?).
• What shifts across individuals and generations is not the capacity itself but how it is allocated between inner and outer rings.

5. Open Questions

• Could digital mediation (AI or persistent chat threads) effectively expand the σ beyond 30, or does it merely stretch the illusion of connectedness?
• Will Gen Alpha’s “always-on” networks create a new equilibrium of smaller, shallower ties rather than larger, deeper ones?
• Do animals and machines occupy a unique category of non-reciprocal yet emotionally costly relationships that need their own accounting outside Dunbar’s scheme?

6. Provisional Conclusion

Dogs do not raise the ceiling of the Dunbar 150, but they do consume slots in the most emotionally salient layers.
Bandwidth is finite.
Variation exists, with σ ~30, influenced by gender, extraversion, and generational norms.