Fig. 1: Digital twin method for comparing the development of social behavior across biological and artificial fish.

First, biological fish were reared and tested in controlled environments (Steps 1–2). Second, we built populations of artificial fish (Step 3), then reared and tested them in digital twins (virtual worlds) that simulated the fish environments (Steps 4–5). Third, we compared the social behavior of the biological and artificial fish (Step 6). We used this method to evaluate whether artificial fish learn fish-like collective behavior and social preferences when raised in the same visual environments as biological fish. We use a circular diagram to emphasize that pixels-to-actions models allow scientists to build models that learn like newborn animals in one study, then iteratively add new studies to the testbed to validate and refine those models.