History of psychology
Psychology has been with us ever since humans have had the ability to ask questions about themselves. Numerous philosophers have considered the nature of the human mind and the reasons behind human behavior.
Psychology as a philosophy:
Monism vs. Dualism
Monists believe that the "mind" and "body" are inextricably connected, ie. they are one and the same. There are several schools of monist thought: materialism and idealism. The materialists believe that the physical world is the only reality there is, and that things can only be explained through physical laws. Idealists believe that the physical world is only in the mind and can therefore be studied only through our own experience.
Dualists on the other hand believe that the mental realm is somehow apart from the physical realm. Specifically, they believe that the laws of the physical world do not give rise to the mental realm. There are several types of dualists. Interactionists like Rene Descartes believe that the mind and body interact, but that the mind can't be studied. Epiphenomenalists believe that the body can influence the mind, but the mind can't generate behavior. They also believe that mental events are outcomes of bodily processes. Psychosocial parallelism says that interactions with the environment directly cause events of mind and body.
Psychology as a science:
It wasn't until 1879, when Wilhelm Wundt set up a laboratory at the University of Leipzig that the scientific method was applied to the study of psychology, and specifically the mind. Not much progress was made initially because Wundt and his followers relied on introspecition, which turned out to be highly prone to error and researcher bias. His contributions remain important because it was the first time somebody tried to apply empiricism and rationalism to the study of the human mind and behavior.
These, and other problems with introspectionism gave rise to Behaviorism. In 1913, John Watson said the mind could not be studied scientifically and said that Psychology as a science should only concern itself with directly observable phenomena. Behaviorism dominated the field of psychology until the 1950's and 1960's when linguist Noam Chonsky critiqued the behaviorist explanation of language acquisition in children. The emerging field of computer science also provided an information processing analogy that convinced many researchers that it was possible to study the mind and not just behavior.
This gave rise to the field of Cognitive Psychology: the study of the mind using the scientific method. There are two general approaches to this problem: structuralism and functionalism. Structuralists believe the mind can be understood by reductionism--ie, to break down cognition into its component parts. Functionalists look at the function of cognitive processes and generalized cognitive patterns.
Schools/Approaches of psychology
There are numerous schools of psychology. Here are a few broad distinctions:
- Clinical psychology: This school of psychology is mainly concerned with the application of psychology to individuals with psychological problems. There are many approaches to this, and the most effective have been those relying on behaviorist and cognitive methods. Several less effective (or unproven), though interesting schools follow:
- Psychoanalysis: Sigmund Freud and Carl Jung were major contributors to this school, which looks to traumatic events in childhood as the causes of psychological problems. The belief is that if you can understand why you are screwed up, then you won't be screwed up anymore.
- Neurolinguistic programming: Started in the 1970's by Richard Bandler and John Grinder, this model primarily relies on using the existing models of cognitive and behavioral psychology and applying those principles to the study of particularly effective therapists. The idea is that if a particular person can do something particularly well, you should find out how they do it (both cognitively and behaviorally) and teach it to other people.
- Humanistic Psychology: This school emphasises the development of individuals over the use of specific behavioral or cognitive techniques. See: Carl Rogers, Abraham Maslow.
- Evolutionary Psychology: This is the study of how various cognitive and behavioral abilities were gained during the course of evolution.
There are numerous other specialties as well:
Some notable contributors to the field of psychology
Source: My own brain