Why is Durkheim described as a functionalist theorist?
Classical functional theorists are defined by their tendency, and education, to focus upon social evolution. Therefore, in regards to Emile Durkheim ideologies, he tended to focus on the importance of a group's ability to survive when they lack strong centralized governments or controlling institutions.
Recognized as the co-founder of modern sociology, Durkheim's research examined the ability of multiple segmented societies ultimately coming together with others, creating a complex idea of solidarity, through the sharing of values and systems of exchanges.
Overall, Durkheim's study of social evolution, and the fact that social evolution examined the functionality of individuals within a society and societies within a greater society, supports the fact that he was a functional theorist. Basically what this means is how something (an individual or group of individuals) functioned within a larger group.
In the end, it is Durkheim's belief that many different factors, such as religion and values, could only be understood through their influence and impact upon the culture or society within which they were examined.