section_path: Study
section_name: Study
paragraph_text: Study
  
  Human behavior is studied by the social sciences, which include psychology, sociology, ethology, and their various branches and schools of thought. There are many different facets of human behavior, and no one definition or field study encompasses it in its entirety. The nature versus nurture debate is one of the fundamental divisions in the study of human behavior; this debate considers whether behavior is predominantly affected by genetic or environmental factors. The study of human behavior sometimes receives public attention due to its intersection with cultural issues, including crime, sexuality, and social inequality.
  
  Some natural sciences also place emphasis on human behavior. Neurology and evolutionary biology, study how behavior is controlled by the nervous system and how the human mind evolved, respectively. In other fields, human behavior may be a secondary subject of study when considering how it affects another subject. Outside of formal scientific inquiry, human behavior and the human condition is also a major focus of philosophy and literature. Philosophy of mind considers aspects such as free will, the mind–body problem, and malleability of human behavior.
  
  Human behavior may be evaluated through questionnaires, interviews, and experimental methods. Animal testing may also be used to test behaviors that can then be compared to human behavior. Twin studies are a common method by which human behavior is studied. Twins with identical genomes can be compared to isolate genetic and environmental factors in behavior. Lifestyle, susceptibility to disease, and unhealthy behaviors have been identified to have both genetic and environmental indicators through twin studies.