Historically, sociologists have usually studied societies like their own, in which people can read and write. Most sociological studies have been of industrialized societies. They would be societies that have a written history. For example, the founder of sociology, Emile Durkheim, made a classic study of Switzerland. Durkheim was French. So the society he studied was essentially his own (that is, European).
Anthropologists generally have studied societies that are more different from the one they were born into. Often these have been tribal societies--where people did not have books but depended on oral traditions for their history and literature. The earlier modern anthropologists studied 19th century and early 20th century Native American cultures, African cultures, and Pacific Island cultures, to name some major ones. Robert Lowie, F.E. WIlliams, and Henri A. Junod are three of these early anthropologists. Their work is very readable, and I recommend it.
This is not a hard and fast distinction like the difference betweeen psychology and biology, but you get the idea.
There are interesting crossovers between anthropology and sociology. Some noted American anthropologists have studied life in India, a literate civilization. Some Indians have been insulted that American anthropologists, not sociologists, went to their country--so you see there can be confusion. Anthropologists often want to be with people as different as possible from their own culture, so it isn't really an insult. To find sameness within difference is a great aesthetic and scientific thrill (that's Aesthetic Realism). Meanwhile, some Indian anthropologists with urban backgrounds have studied tribes of India, their own country but a different culture within it. An American anthropologist I know studied life in China, a 5000 year old civilization, while a Chinese anthropologist was successful in studying Native American culture among Pueblo people.
And also -- some American anthropologists have studied American culture: Hortense Powdermaker wrote a book on her research, "Hollywood, the Dream Factory." For the book "Middletown," the Lynds, a husband and wife team, used anthropological methods--including living with the people--to study a midwestern city. There are crossovers all over the place.
One reason there are crossovers is that the core concepts of both anthropology and sociology are virtually identical, although different terminology is, in part, used. And both fields study people living in societies, which is anyone, really.
Anthropologists tend to study a whole culture (or a city or town or village as a microcosm of the culture) while sociologists tend to take on particular problems in part of a culture, often using statistical analysis to do it. Most anthropology books, called ethnographies, aren't statistical in the same way as a study of fallout shelters in Greenwich, Connecticut, which I was part of in 1962 or so. That was sociology.
So you get the picture, I hope, that there's lots of variation, but there is a real difference between the two fields.
If you want to look at my anthropology and sociology website, you'll see that I write about how tribal people and people in cities are like one another, while honoring the differences too. And that comes from my study of the philosophy Aesthetic Realism, the founder of which, Eli Siegel, showed that "The deepest desire of everyone is to like the world on an honest basis." The principles of Aesthetic Realism are true about people in every culture, and so they bring together anthropology and sociology in a new and more complete way, and represent the basis for a science of humanity as one field.
Source(s):
http://www.perey-anthropology.net