A STUDY WAS CONDUCTED TO ANALYZE THE SOCIAL ISOLATION AND UPWARD MOBILITY OF FAMILIES LIVING IN A SHANTY TOWN AND A PUBLIC HOUSING PROJECT IN PUERTO RICO, AND OF NEGRO FAMILIES IN A GHETTO IN SYRACUSE, NEW YORK. DATA WERE COLLECTED BY MEANS OF PARTICIPANT OBSERVERS AND INTERVIEW SCHEDULES. IT WAS FOUND THAT THE POOR DO NOT LIVE IN A SUBCULTURE DEFINED BY A PARTICULAR VALUE SYSTEM, BUT RATHER THAT THEY DO NOT ENTER THE LARGER DOMINANT SOCIETY BECAUSE THEY LACK OPPORTUNITIES AND BECAUSE THEY DO NOT HAVE A SUPPORTIVE NEIGHBORHOOD ENVIRONMENT. IN PUERTO RICAN SOCIETY UPWARD MOBILITY IS NOT IMPEDED BY RACIAL BARRIERS, AS IT IS IN THE UNITED STATES, AND THE LOW-INCOME PUERTO RICAN CAN MORE RAPIDLY ACHIEVE A HIGHER STATUS. IN THE UNITED STATES RACIAL EXCLUSION HAS DISORGANIZED THE NEGRO HOME AND COMMUNITY AND HAS CAUSED IDENTITY PROBLEMS FOR THE NEGRO, WHOSE HOSTILITY IS OFTEN TURNED INTO ACTS OF DESTRUCTION AGAINST THE COMMUNITY ITSELF. IN CONTRAST WITH THE PUERTO RICAN HOUSING PROJECT COMMUNITY AND THE NEGRO GHETTO, IN THE PUERTO RICAN SHANTY TOWN COMMUNITY SOLIDARITY AND PRIDE ARE FOSTERED BY THE EXISTENCE OF A LOCAL LEADERSHIP, AND THE MALE PLAYS A DISTINCT ROLE IN THE FAMILY AND THE COMMUNITY. THE HOUSING PROJECT AND THE GHETTO COMMUNITIES DEPEND ON OUTSIDE AGENCIES TO MAINTAIN SOCIAL CONTROL IN THE NEIGHBORHOOD. TO PROMOTE ASSIMILATION, POLICY MAKERS SHOULD ENCOURAGE THE PARTICIPATION OF THE POOR IN LOCAL AFFAIRS. TABLES ARE INCLUDED. (LB)