Denmark's (1979) functional definition of profound deafness is adopted. Deaf individuals are aware of sound and may detect vibration but they have a limited facility of speech. Conrad (1979) and Rodda (1970) have shown the low level of scholarly achievement of such individuals. Denmark suggests that as young adults, they face the hearing world largely isolated from their parents, their friends and the professionals who advise them. This study is an attempt to explore the social problems brought about by such isolation. The thesis investigates the individual profoundly deaf young adult's self concept in relation to others. A unique form of Repertory Grid interview (Kelly, 1955)using sign language was developed, and was successfully employed with the majority of individuals. However, it became apparent that a substantial minority were lacking, sometimes wholly, in a structured form of language. A pre-interview routine was used to determine the form of investigation appropriate to the individual - an interview using sign language, or one placing heavy dependence on non verbal communication (such as mime and body language). Both forms of investigation enabled an 'existential phenomenological' description of the self-awareness of the individual to be produced. In the larger group, the procedure followed was near to the orthodox analysis of Rep Grids; in the smaller group, analysis involved a greater degree of interpretive intuition. Justification for the judgements made in each case is provided. The findings are reported in the form of case studies: 40based on Rep Grids, 10 on non-verbal interviews. Thematerial provides an advance in the understanding of the experience of the profoundly deaf young adult. Exuberance and vitality feature in the majority group interviewed by Repertory Grid method. Examples of isolation and of intense personal relationships are found in the minority group. The deaf have a special concern with: those whoaccept them and those rejected by them; dependence upondeaf peers rather than hearing adults; the apprehension of success and personal failure. The main finding of this research is that the young adult deaf do possess a self-awareness and this self-awareness is that of the normal individual. Theidiosyncracies of deaf behaviour are especially wellrepresented in the smaller group. This research confirms the suggestion of Denmark that the majority of deaf individuals referred for psychiatric help are not suffering from mental illness. The study also provides research evidence for necessary changes in the early education and upbringing of the deaf.