Maintain weak ties for information and opportunity

The 50-to-150 layer isn't maintenance overhead — it's your network's reach.

Why it works

Granovetter's weak-ties research (separate from Dunbar but complementary) showed that information, job leads, and new introductions disproportionately flow through acquaintances rather than close friends — because close friends share your existing information set, while acquaintances bridge to different social worlds. Dunbar's outer layers (50-150) are the zone where weak ties live. Maintaining occasional contact with this layer is not inefficiency but access to the diversity of information and connection that close friendships cannot provide.

How to do it

1. Stay in light, low-frequency contact with your 50-150 layer: a like, a brief reply, an occasional message when something reminds you of them.
2. When you need a referral, introduction, or piece of information, scan your outer layers before defaulting to your inner circle.
3. At social events, invest some contact in people you do not already know well rather than clustering entirely with your inner circle.
4. Keep a light record of outer-layer contacts so you can remember who is connected to what.

Evidence

Granovetter's research on weak ties and job-finding is a seminal empirical finding; the overlap with Dunbar's outer-circle concept is theoretical but highly coherent — Dunbar's 50-150 layer maps directly onto the social space where weak ties operate. (observational)

Granovetter's research on information flow does not directly test Dunbar's layer model; the integration of the two frameworks is an inference, however plausible.

Sources

• Granovetter, M. S. (1973). The strength of weak ties. American Journal of Sociology, 78(6), 1360–1380.

Common mistake

Letting outer-layer relationships go entirely quiet because they seem less important than inner-circle bonds, then finding that the network bridge has atrophied when you actually need it.