Psychology is the scientific study of behavior and mental processes, encompassing various subfields such as cognitive, physiological, developmental, social, and clinical psychology. Key goals include describing, understanding, predicting, and controlling behavior, with contributions from different schools of thought including structuralism, functionalism, and behaviorism. The field has evolved since Wilhelm Wundt established the first psychological lab in 1879, leading to modern approaches that emphasize both negative and positive human experiences.