Many sociology courses explore the topic of relationship roles within family dynamics. Within every family unit each person plays a specific role, whether they are aware of it or not. One parent may be the nurturer while the other is the disciplinarian, or perhaps one spouse is in charge of all the house duties while the other takes care of the finances. An interesting sociology topic to consider for a research paper is to examine how these roles evolve, how they have changed over time -- if they have -- and whether the relationship roles support a social norm. Another potential research angle to take is to study how gender shapes social relationship roles.
One of the things that sociology is concerned with is how communities are established. Sociologists look for demographic trends that may lead to theories about high-class societies and the types of people who are a part of them, versus lower-class societies and their inhabitants. For a research paper, expand on these topics to find out how exclusive certain communities are over others, and whether this can be related to classism, which is discrimination against people from another class. Digging deeper, look at how classism evolved and find examples of how this form of discrimination works both ways. Citizens from underprivileged communities can be guilty of classism just as citizens from privileged communities can.
Pressure exists among societies for its members to stay in line with what the majority consider to be social norms. Social pressures, such as which religion to practice, what gender to be attracted to, which political party to affiliate with and what type of career to choose, can affect how people behave and think within a society. For your research paper, examine how the pressure of fitting into a social norm has an affect on people and relationships. You may even want to conduct a survey to ask random subjects if they have ever felt pressured to do something because society "made" them. Work your findings into the research paper to conclude that social pressures are effective strategies for maintaining social order and balance.
For your research paper, explore the work of a well-known social theorist, such as Karl Marx. Discuss main sociology projects or experiments that he was concerned with and what his findings revealed about societies. Expand on his work by relating the information to current times, and demonstrate how the trends in sociology have remained the same or changed since his original theories.