THIS SOCIOLOGICAL ANALYSIS DESCRIBES THE LOWER-STATUS URBAN AND RURAL FAMILIES IN PUERTO RICO. THE "JIBAROS," THE RURAL POOR OF THE HIGHLANDS, ARE LANDLESS AGRICULTURAL WORKERS WHO ARE MORE ISOLATED, LESS LITERATE, AND LESS ACCULTURATED TO URBAN LIFE THAN OTHER PUERTO RICANS. THEY TEND TO BE IDEALIZED AS THE PROTOTYPES OF THE ISLAND FOLK CULTURE. THEIR FAMILY STRUCTURE IS CHARACTERISTICALLY MALE-DOMINATED AND AUTHORITARIAN. "JIBARO" WOMEN TEND TO COMPENSATE FOR THEIR INFERIOR POSITIONS THROUGH CLOSE ATTACHMENT TO THEIR OFFSPRING, ESPECIALLY TO THEIR SONS. THE COASTAL POOR, VERY SIMILAR TO THE "JIBAROS" OF THE HIGHLANDS, ARE LANDLESS LABORERS ON THE SUGAR CANE PLANTATIONS WHO ARE ENTIRELY DEPENDENT ON WAGES FOR THEIR SUBSISTENCE. MORE A UNIT OF CONSUMPTION THAN PRODUCTION, THE FAMILY OF A COASTAL SUGAR CANE WORKER USUALLY LIVES IN CROWDED HOUSING AND LACKS THE DIGNITY OF THE "JIBARO" FAMILY. THE URBAN POOR ARE MUCH MORE DIVERSIFIED AND LEAD A MORE MARGINAL EXISTENCE. AMONG ALL LOWER-STATUS PUERTO RICANS, CHILDREN ARE HIGHLY VALUED, WHETHER FROM CONSENSUAL OR LEGAL MARRIAGES, AND GODPARENTS PLAY A PARTICULARLY IMPORTANT ROLE IN THE FAMILY LIFE. HOWEVER, POPULATION DENSITY ON THE ISLAND IS REACHING CRITICAL PROPORTIONS AND THE COMMONWEALTH GOVERNMENT IS ENCOURAGING CONTRACEPTION, INDUSTRIALIZATION, AND EMIGRATION TO RELIEVE THE PRESSURE. BUT URBAN ENVIRONMENT ON THE U.S. MAINLAND CHANGES TRADITIONAL SOCIAL CONTROLS, SOCIABILITY PATTERNS, AND HOMEMAKING PRACTICES, AND FORCES NEW LIFE STYLES AND VALUES. THUS THE SOCIAL CHANGE OCCURRING ON THE ISLAND TRAPS THE PUERTO RICAN BETWEEN THE INSTABILITY OF LIFE THERE AND THE INSECURITY HE FEELS ON THE MAINLAND. (NH)