The word psychology comes from the Greek ('soul', 'mental activity') psico- and - logia ("study"). It is the science that studies mental processes using three dimensions: cognitive, affective, and behavioral.
Devoid of speculation, scientific psychology and metaphysics, was born in the 19th century. With psychophysics, whose purpose is to measure the mental in a quantitative manner and seeking to establish a link between the physical and the psychological psychology is now part of objective science.
The first scientific psychology laboratory was established by Wilhelm Wundt in Leipzig (Germany). Therefore, psychology continues to provide important inputs to the mental processes empirical knowledge and conduct.
In the 20th century, North American driver psychology and Soviet psychology coincide in the experimental presentations and epistemological positivists. However, discipline is part of the natural sciences and conduct replaces the mind as an object of study.
However, towards the half of the century, cognitive psychology retrieves the study of mental, but any processes while preserving the experimental methods of the Behaviorism (or behaviourism). The notion that science is being built from the empirical and objective is never abandoned.
The combination of theories and behavioral and cognitive practices have made possible the appearance of techniques to resolve individual and social problems, as well as the development of scientifically proven therapies.
In addition to scientific psychology, it is appropriate to mention alternative Psychology (also known as pseudopsychologies) who reject the scientific method. This is the case, for example, of parapsychology, which is criticized by many experts.