One of the most important contributions in Roland Posner’s work (1993) was the extension and development of the Gricean paradigm on meaning (1957) in a systematic framework, providing thus a general foundation of semiotic phenomena. According to this approach, communication consists in behaviors or artifacts based on reciprocal assumptions about the intentions and beliefs of the subjects involved in a semiotic exchange. Posner’s model develops with clarity the hierarchical relationships of semiotic phenomena of different complexity, from simple pre-communicative behaviors (like indicating or signaling) to full communicative acts. Not only limited to linguistic communication, this framework can be successfully extended in the description of all kind of sign production, from gestures to artifacts. This article discusses a key point of this paradigm, namely our faculty to at-tribute mental states to other individuals through the observation of their behavior, artifacts or texts. New insights from neuropsychology and developmental psychology are discussed in supporting the validity of this model of communication.