History and Approaches
Psychology began in Ancient Greece through the minds and discussions of Aristotle, Plato, and Socrates. Socrates believed that the mind and body existed separately, and the mind would continue on without a living body. Socrates also believed, along with Plato, that all thoughts and knowledge existed upon birth innately. Aristotle, however, contradicted such a belief stating that knowledge grew through experiences, rather than preexisting in the mind. Frenchman Descartes agreed with Aristotle and Socrates, and believed the brain contained "animal spirits" which flowed throughout the body in nerves.
Many years later, psychology found its first empirical laboratory in Leipzig Germany under Wilhelm Wundt. Wundt's students Edward Titchener and William James went on to form structuralism and functionalism respectively. Structuralism focused on the structure of the mind. Using introspection, or looking into ones mind for answers, Titchener believed the answers could be sorted easily into several categories in order to determine certain mind structures. Instead, he ended the experiment after tens of thousands of categories. James focused on the functions of the mind rather than structures. James believed thinking, like other senses, existed because it is adaptive. Thus, he looked at emotions, willpower, memories, habits, and general consciousness to define their functions. James also admitted the first ever woman psychologist, Mary Calkins, to his class at Harvard and wrote the first ever psychology text book. Harvard denied Calkins' doctorate degree and instead offered a bachelors from its sister school Radcliffe. Calkins protested the degree from Harvard, despite receiving no degree, she went on to become the first female president of the American Psychological Association in 1905. Harvard posthumously awarded Calkins her degree nearly one hundred years later.
Until the 1920's, early psychologists defined psychology as the study of mental life. With the rise of behaviorism from 1920-60, John B. Watson and B.F. Skinner redefined psychology as the "scientific study of observable behavior". Behaviorism focused on studying how people behaved and reacted in certain situations.
The 1960's ushered in yet another perspective; humanistic psychology. Humanistic psychologists like Abraham Maslow centered their studies on the importance of the current environmental influences along with personal needs for love and acceptance. Also in the 60's, the movement for cognitive neuroscience came into view. Neuroscience studied the connection of brain activity with mental activity, and defined psychology as "the science of behavior and mental processes".
With the advent of psychology and the evolutionary approach, every psychological matter is also a matter of nature vs nurture. Today, psychologists find that most everything is a result of both rather than one or the other. The resulting conclusions are therefore found by a biopsychosocial approach, which provides three levels of analysis on the biological level, psychological level, and social level. Psychology today is divided into subcategories of approaches including biological, evolutionary, psychodynamic, behavioral, cognitive, humanistic, and social-cultural. All of which split again into several useful branches of psychology.