Hi, litany239,
The MPH is a versatile degree. If you decide to apply to an MPH program, you will be able to select a focus area of most interest to you and in which you take your specialization courses and get your practice experiences (i.e., an internship or practicum). At most schools, at least those in the USA, you can tailor your education to your career goals. For example, if you want to be an epidemiologist, then you can take the majority of your classes in epidemiology, or if you want to design community health programs as a career, then you should consider health behavior and evaluation classes. In fact, at most schools, you will select a concentration when you apply. It sounds like you might want to consider a track with focus on the social sciences. These concentrations are usually labelled Community Health, Social and Behavioral Sciences, or Health Education. The concentration names vary by school, but you'll see the content is largely the same. However, you'll still have to take a set of core classes that every worthwhile MPH program requires as part of its accreditation.