Psychology  is an academic and applied discipline involving the scientific study of mental processes and behaviour. It also refers to the application of such knowledge to various spheres of human activity, including problems of individual's daily life and the treatment of mental illness.The development of modern scientific psychology was pioneered by studies that resulted in many schools of thought.Psychology started emerging as a scientific discipline in 1879 when Wilhem Wundt, a German physiologist opened the first psychology laboratory in Germany.Structuralists studied the mind by bringing people in laboratories and asking them to respond to stimuli.this method was known as introspection. Later John B Watson an american psychologist said that introspection was invalid and unreliable because of its subjective nature- only the individuals can observe and understand their mental processes...