An anthropologist is a person engaged in the practice of anthropology. Anthropology is the study of aspects of humans within past and present societies. Social anthropology, cultural anthropology and philosophical anthropology study the norms and values of societies. Linguistic anthropology studies how language affects social life, while economic anthropology studies human economic behavior. Biological (physical), forensic and medical anthropology study the biological development of humans, the application of biological anthropology in a legal setting and the study of diseases and their impacts on humans over time, respectively.