This paper aims to investigate non-verbal communication displayed in clinical settings from the perspectives of relational psychoanalysis and ethology. After revisiting Freud’s biological perspective on neurosis from his first theoretical constructions, we will initially set a dialogue between psychoanalysis and ethology through concepts that prove to be interchangeable and fruitful to both sciences. This discussion brings us to the dilemmas inherent to the concept of drive and the role of representation in Freudian metapsychology. Hereafter we will go deeper into relational psychoanalysis and attachment theory from which we derive important considerations about primitive aspects of the psychic constitution and non-verbal communication. The sensory dimension of the experience and the intersubjective processes will be addressed as essential factors in the individual s development. Finally, we will offer special attention to the management of nonverbal communication in clinical settings. We will then highlight through an eto-psychoanalytic approach of primitive emotional suffering the sensory phenomena displayed in certain psychopathological situations. We will discuss the phylogenetic adaptations acquired throughout the evolutionary process and how they introduce a new understanding to communication processes mediated by the body that may assist the analyst in understanding the sensory marks left by early trauma. We will defend the hypothesis that in every subject there is a nucleus inaccessible through speech which manifests itself clinically and how this nucleus is especially present in the analysis of critically ill patients whose psychic impairment is found at deeper levels of the personality.