Briefly reviews the literature on persistent peoples and middleman minorities, two ethnic types that seem to apply to the Cubans of Puerto Rico; describes the basic socioeconomic characteristics of the Cuban population, including occupation, education, income, and residence patterns; presents data on the Cubans' social networks, marriage patterns, and ethnic attitudes; attempts to integrate the psycho-cultural and social-structural approaches to the Cuban community; and concludes with a general comment on the relationship between ethnic identity and socioeconomic adaptation. -from Author