Introduction
The application , form , functions , and relevance of psychology has always been debated by many scientists . In the 19th century , the earliest psychological research performed a physiological experimentation of how the brain and nerves work together in the production of the observable actions and behaviors of animals . This was later termed as applied psychology that evolved into many other forms of experimental psychology based on the views of the researchers on how psychological testing should be applied and conducted . During the 19th century, the strongest form of psychology evolved of behaviorism (Schulz, P & Schultz, S 2007 Behaviorism was an American phenomenon and it emphasized the possibility and importance of learning through perseverance . Many psychologists have tried to improve and change the practices and theories of American behaviorism in ages . Some of the most influential psychologists are B. F.
Skinner, John B. Watson, and Edward C. Tolman. The perspective of psychology appears to be changing as the field of psychology is progressing (Goodwin, 2005). However, there are some perspectives that have core values and they have remained to be steadfast in today ’s pool of theories . The theories of these three psychologists are still the foundation in many schools of thought , in psychology .

John B.Watson was born in 1878 and went to college at the age of 16. In 1913, Watson was invited in Columbia University where he shared his theory of behavioral psychology (Weiten, 2012).
The speech delivered on this day was published on the same year with a title on Psychology as behaviorist views it . This publication was known as the behaviorist manifesto. The manifesto assigned psychology to natural science , it articulated a clear set of goals , accepted a revolutionary model of behavior, and rejected introspective based psychology. Watson studies philosophy and from what he learnt started forming his own theories on behavior that was known as behaviorism. Behaviorism is referred to as the philosophy of psychology that proposes that everything that organisms do including thinking , feeling , and acting should be regarded as behaviors . The theory of Watson was considered as classical behaviorism; thus , known as classical conditioning (Schulz,
P & Schultz, S 2007). Classical conditioning is the form of learning where a neutral stimulus elicits a response after it has been paired with a stimulus that brought the response . His view on behavior was that it was purely obtained . According to Watson, he believed that people experienced no emotions , and they were a response of other stimuli . The goal of Watson for classical behaviorism was the creation of a more objective science.

According to this psychologist , he believed that one must observe behavior , make predictions , and lastly determine casual relationships . Watson viewed psychology as experimental and objective . According to him, he considered behavior as being the relationship between the stimuli and response of the subject to it (Weiten, 2012). This psychologist viewed psychology as not being a true natural science . His focus was the study and modification of the environment of the subject.
Watson believed that it was possible for one to obtain desired behavior through controlling their environment . A popular experiment of Watson is that of “Little Albert”. In the experiment, he paired a white rat which was the neutral stimulus with a loud noise as the unconditioned stimulus to elicit a frightened response as conditioned and unconditioned response.
Based on the work of Watson, B.F. Skinner took behaviorism to a new level. Skinner was able to develop his theories of behaviorism when he was at Harvard in 1930. This psychologist was a close follower of Watson and conducted several major studies in conditioning. He was able to further his study through developing the theory of