Claude Haiku 4.5 replication
Homophily under model substitution
A scaled-down topic simulation tests whether LLM agents preferentially engage with semantically similar others when the model family changes from GPT-3.5 to Claude Haiku 4.5.
Agents
100
Rounds
12
p-value
< 0.001
Canonical result
Reproduces, with attenuated magnitude.
Final modularity sits above the degree-preserving bootstrap null, while assortativity and content-engagement correlation remain weakly positive.
Mechanism
Agents post, read a mixed feed, and choose 1-3 posts to like, follow, or ignore.
Measurement
Weighted engagement graphs, Louvain communities, MiniLM embeddings, and a degree-preserving null.
Constraint
No prompt tells agents to seek similar others. The homophily signal has to emerge.