Perhaps it means cultures that look inward and constantly recycle their own tropes are more likely to be unstable than cultures that look outwards and have a positive attitude to novelty.

Whether it's an AI eating its own training data, a human stuck in an empty cell and forced to live with just his/her own thoughts, or a culture believing its own myths and aggressively punishing insiders and outsiders who challenge them - it's all solitary confinement. And we know how that goes.