cognitive and evolutionary sciences. The field employs methods and theories from a very broad range of disciplines, including: cognitive psychology, evolutionary psychology, cognitive anthropology, artificial intelligence, cognitive neuroscience, neurobiology, zoology, and ethology. Scholars in this field seek to explain how human minds acquire, generate, and transmit religious thoughts, practices, and schemas by means of ordinary cognitive capacities. Hallucinations and delusions related to religious content occurs in about 60% of people with schizophrenia. While this number varies across cultures, this had led to theories about a number of influential religious phenomena and possible relation to psychotic disorders. A number of prophetic experiences are consistent with psychotic symptoms, although retrospective diagnoses are practically impossible. Schizophrenic episodes are also experienced by people who do not have belief in gods. Religious content is also common in temporal lobe epilepsy, and obsessive–compulsive disorder. Atheistic content is also found to be common with temporal lobe epilepsy. Comparativism Comparative religion is the branch of the study of religions concerned with the systematic comparison of the doctrines and practices of the world's religions. In general, the comparative study of religion yields a deeper understanding of the fundamental philosophical concerns of religion such as ethics, metaphysics, and the nature and form of salvation. Studying such material is meant to give one a richer and more sophisticated understanding of human beliefs and practices regarding the sacred, numinous, spiritual and divine. In the field of comparative religion, a common geographical classification of the main world religions includes Middle Eastern religions (including Zoroastrianism and Iranian religions), Indian religions, East Asian religions, African religions, American religions, Oceanic religions, and classical Hellenistic religions. Classification In the 19th and 20th centuries, the academic practice of comparative religion divided religious belief into philosophically defined categories called world religions. Some academics studying the subject have divided religions into three broad categories: world religions, a term which refers to transcultural, international religions; indigenous religions, which refers to smaller, culture-specific or nation-specific religious groups; and new religious movements, which refers to recently developed religions. Some recent scholarship has argued that not all types of religion are necessarily separated by mutually exclusive philosophies, and furthermore that the utility of ascribing a practice to a certain philosophy, or even calling a given practice religious, rather than cultural, political, or social in nature, is limited. The current state of psychological study about the nature of religiousness suggests that it is better to