Anthropology as a science is divided into four distinct sub-fields: cultural anthropology (social anthropology), archaeology, linguistic anthropology, and biological (physical) anthropology. Depending on the sub-field, anthropologists' responsibilities vary widely.

Social anthropologists, for instance, research and study only social and cultural behaviours. They may be employed as social scientists for government or research laboratories, conducting surveys and analyzing data to develop new and more effective social policies. Census studies, for example, are often conducted by social anthropologists. These scientists also work in disease prevention and aid in the development of new crowd control techniques. In many ways, social scientists are sociologists who work to implement their theories in a variety of practical applications.

Policy and program analyst positions are also available for social anthropologists. In these positions, scientists study and analyze government or corporate policies and programs. They assess whether existing programs are effective and whether social reform plans can be improved.

In the field of archaeology, anthropologists uncover humanity's hidden history through the discovery of artifacts and structures left behind by previous civilizations. They contribute supporting evidence to historical documents, or even uncover stories from the past that have not yet been told. That which is learned from archaeologists' discoveries can aid in improving many aspects of modern culture, or avoiding difficulties encountered in the past.

While archaeologists generally work in the field, excavating artifacts and studying historical structures, some also find employment as university professors or museum curators. Both curators and archivists organize and analyze large collections of evidence brought in from the field. They help interpret information from these collections and bring it to the attention of the public and community. Additionally, they oversee technical aspects of preservation and the display of exhibits within the museum.

Linguistic anthropologists research language development and how it applies to modern cultures. For example, they might examine why the dialect of people in the southeastern United States carries a negative stereotype or why the Inuit have 15 different words to describe snow. The results of these studies are used to understand major concerns specific to each culture and develop more effective intercultural relationships.

Those employed in the science of biological anthropology study the development of the human species, especially theories that homo sapiens may have evolved from other primates. Biological anthropologists utilize fossil evidence to develop extensive data on human ancestry and how certain physical structures, such as the mandible or opposable thumb, may have developed. They also use this evidence to study how some behaviours may have evolved and, in the case of new fossil evidence, propose new species. To obtain non-fossil evidence, biological anthropologists study primates in their natural environment in hopes of uncovering data relevant to humanity.