Model-Based Assimilation Transmits and Recombines World Models

We argue that imitation, in addition to the typical roles it plays in culture, additionally supports the social transmission and recombination of world models. We propose a learning pathway called “model-based assimilation”, which uses imitation to shape the statics of experience, and “hijacks” existing individual learning mechanisms supporting model-based learning (e.g., hippocampal replay). This pathway is computationally cheaper than explicit Theory of Mind inference, but nevertheless allows for the social recombination of knowledge across multiple brains. Our theory provides important insights into why our close relative, the chimpanzee, imitates poorly and why humans acquired cumulative culture.