Final answer:
Qualitative research methods, particularly ethnographic field research, or participant observation are used by sociologists to explore the reasons behind people's behaviors and social phenomena, providing depth of understanding.
Step-by-step explanation:
The type of research method that attempts to answer the question, "Why are they doing that?" is generally a qualitative research method. Within sociology, qualitative methods such as ethnographic field research, participant observation, in-depth interviews, and case studies are most aligned with exploring and understanding the reasons behind people's behaviors and social phenomena. These methods enable researchers to gather rich, detailed information, providing insights into the social context and the symbolic meanings that people assign to their actions and interactions.
When sociologists pose a question pertaining to understanding the reasons for certain behaviors, it leads to an exploratory form of research where the focus is to gain depth of understanding rather than to quantify. Methods like participant observation or ethnographies are immersive and involve researchers actively engaging with the research subjects in their environment, thereby allowing an examination of the subtle nuances of behavior and social interaction.