In Group Psychology and the Analysis of the Ego, Sigmund Freud attempted to apply his understanding of the unconscious forces active in the mind of the individual to certain aspects of the mental life of groups. In this chapter, the author labeled as primitive groups those which follow the pattern of Freud's "unorganized" groups and Wilfred Bion's basic assumption groups and those which follow the pattern of Freud's "organized" groups and Bion's work groups as sophisticated groups. The reflexive nature of the psychoanalytic work requires both the primitive and the sophisticated dyads to remain vital and to remain in contact with one another. The clinical sign of this contact is a tension between the two dyads that is experienced by both patient and analyst as a sense of insecurity in the analysis. Clinical psychoanalysis, the work between one patient and one analyst, is a very peculiar Specialized Work Group.