This paper provides a summary of new results coming from developmental infancy research demonstrating preverbal infants' early competence in understanding and learning from the intentional actions of other agents. The reviewed studies (using violation-of-expectation and observational learning paradigms) provide converging evidence that by the end of the first year infants can interpret and draw systematic inferences about other agents' goal-directed actions, and can rely on such inferences in observational learning when imitating others' actions or emulating their goals. To account for these findings it is proposed that young infants possess a non-mentalistic action interpretational system, the 'teleological stance' (Gergely and Csibra 2003) that represents actions by relating three relevant aspects of reality (action, goal-state, and situational constraints) through the inferential 'principle of rational action', which assumes that: (a) the basic function of actions is to bring about future goalstates; and that (b) agents will always perform the most efficient means action available to them within the constraints of the given situation. The relevance of these research findings and theproposed theoretical model for how to realize the future goal of epigenetic robotics of building a'socially relevant' humanoid robot is then discussed.