One shared memory that keeps fading, three minimal agents, no boss — and a story that outlives every note that carried it.
TL;DR: Give a few bare-bones agents nothing but a shared notepad that constantly fades, and they spontaneously build a culture — a story they keep alive together, long after any single note has decayed to nothing. No coordinator, one tiny rule. Runs on a laptop.
Three agents share one whiteboard. Every tick, everything on it fades; a note left alone dies in ~4 ticks. Each tick an agent scribbles a noisy observation, and a swarm agent also reinforces whatever's currently strongest. That's the whole rule. It's stigmergy — how termites build cathedrals by reacting to each other's mud (Grassé, 1959) — and the same dynamic that lets populations of agents settle on shared conventions (Perez et al., 2024).
| ❌ Each on its own | ✅ The swarm | |
|---|---|---|
| A shared story exists | ||
| 11% of ticks | ||
| 100% | ||
| Same story tick-to-tick | 3% | |
| 99% |
pad[observation] += 0.3 # everyone adds a little noise
if imitate: # the entire "culture" rule:
leader = strongest(pad) # reinforce what the group already backs
pad[leader] += 1.0
Tick 0: group rallies around "water down"
Tick 100: group still holds "water down"
...but that original note faded to ~8e-31 within a few ticks.
It survived only because the agents rewrote it 300 times.
The story is 100 ticks old; the note that started it has been gone since tick ~4. What persists isn't any note — it's the meaning, re-inscribed by the group. It's the Ship of Theseus: no original plank left, yet the ship sails on. Reseed and a different story wins — the agreement is what's real.
We keep trying to fix agent memory with bigger storage. This says a group of forgetful agents can hold knowledge no single one could, just by reminding each other. Persistence becomes a property of the society.
These agents can't remember much alone. Together, on a whiteboard that won't stop erasing itself, they keep a story alive as long as they care to. That's culture.
git clone https://github.com/Shridhar-2205/secret-lives-of-agents
cd secret-lives-of-agents/02-emergent-culture && python demo.py
Shridhar Shah — Senior Software Engineer on the AI team at Cisco. GitHub · LinkedIn
Sources & further reading:Stigmergy (Grassé, 1959) — the biology of indirect coordination · Park et al.,[(2023) · Perez et al.,]Generative Agents: Interactive Simulacra of Human Behavior[(2024).]Cultural Evolution in Populations of Large Language Models