In the second half of the 19th century (1879), psychology became a more organized experimental field of study when Wilhelm Wundt founded the first phychological research laboratory in Leipzig, Germany. Wundt and others of that time approached psychology with: ?Every physical event has a mental counterpart, and every mental event has a physical counterpart.?

At this time, Ivan Pavlov also made important contributions to the science of psychology. Pavlov developed procedures associated with classical conditioning. One of his well known experiments was conditioning a dog to associate a bell ringing (stimulus) with food. The effect: after a few repetitions, the dog produced a physical response to the sound of the bell - he salivated. Pavlov referred to this learned relationship as a conditional reflex (now called Conditioned Response).

History of Psychology: Applied Psychology

In the 1890s, soon after the development of experimental psychology, various kinds of applied psychology began to appear as well:

* scientific pedagogy (science of teaching)

* educational theory

* application of psychology to industry, law, and other professions

* first psychological clinic

* first program of mental testing

One of the most well known psychiatrists, Sigmund Freud, developed an independent approach to the study of the mind called psychoanalysis, which has been widely influential.

History of Psychology: Behavioral Psychology

The 20th century saw the formulation of behaviorism which was popularized by B.F. Skinner who was recently named in a survey as the most influential psychologist of his time. Behaviorism proposed limiting psychological study to that of overt behavior, since that could be quantified and easily measured. Skinner influenced education as well as psychology. He asserted that positive reinforcement is more effective at changing and establishing behavior than punishment. This theory has also influenced parenting methods.

Cognitive Psychology

The final decades of the 20th century saw the decline of behaviorism and the rise of an interdisciplinary approach to studying the human mind ? how we think, known collectively as cognitive science. Such an understanding of the mind may be applied to other research domains, such as artificial intelligence.