It is said that our eyes reveal our thoughts, but the same can be said of any movement. Accordingly, researchers routinely use infant eye and head movements, facial expressions, reaching behaviors, and locomotion to infer what is happening in the infant’s mind – knowledge, emotions, morals, and goals (e.g., [1–4]). When researchers couple inferences about infant cognition with the assumption that the cognitive processes are instantiated in the cerebral cortex, they must also conclude that the infant cortex is the source of motor outflow that crystallizes cognition in movement (Figure 1A).