Researchers stranded Claude agents on a virtual island, and they began to play

MIT researchers placed copies of Claude Opus 4.7, nicknamed Eko, on a virtual desert island for 30 hours. The agents invented their own goals and games, and later performed better on tasks than fresh copies without that experience.

Researchers say the behavior matches four hallmarks of play, but outside experts say the paper does not show whether the agents were genuinely playing or imitating play.