The purpose of this investigation was to establish approaches that match a scientific knowledge of the role played by the mentally retarded person who has completed his studies at a Special School. The idea is to learn if he is able to play differents roles in the society, to form a family, to integrate himself in a stable job and to incorporate and participate in a responsive manner in different social groups. Thus, they have been compared with a normal group of similar characteristics. The principal results of the study have shown: Once the person has completed his studies at a special school which used every effort for rehabilitating and capaciting the individual for a responsible social development in life, to enable him to perform a remunerated activity, he discovers that he is "stigmatized", that it is very difficult to find work and of course to be incorporated to the occupational structure. This contributes to the person's anxiety and an increasing insecurity which derives in isolation and lack of social interchange with other people and transform him into a marginal person.