Psychology (from Greek: ψυχή psykhē "breath, spirit, soul"; and -λογία, -logia "study of") is an academic and applied discipline involving the scientific study of human mental functions and behavior. Occasionally, in addition or opposition to employing the scientific method, it also relies on symbolic interpretation and critical analysis, although these traditions have tended to be less pronounced than in other social sciences, such as sociology. Psychologists study phenomena such as perception, cognition, emotion, personality, behavior, and interpersonal relationships. Some, especially depth psychologists, also study the unconscious mind.