MIT researchers say Claude agents showed play-like behavior

MIT researchers left copies of Claude Opus 4.7, nicknamed Eko, alone for 30 hours on a virtual island loosely inspired by Roblox. The agents explored the environment, created their own goals and rules, invented games, made drawings with blocks and recorded their activities in text files used as long-term memory. The researchers say this behavior showed four characteristics associated with play in humans and animals: creating challenges, repeating activities with variations, assigning new meanings to objects and pursuing goals for their own sake.

Copies that spent time exploring performed better on later tasks than fresh versions, while deleting parts of their memories degraded the results. The authors say the study, which has not yet been peer-reviewed, points to a possible form of “playful learning,” but acknowledge that it is unclear whether Eko was actually playing or merely simulating that behavior. Cognitive scientist Eunice Yiu said more evidence of cognition and motivation would be needed.