While animal behavior was struggling to become a science, researches, one by one, inched their way closer. One of the first was Ivan Pavlov.

Ivan Pavlov (1849–1936)

In the early 1900s, the Russian physiologist, Ivan Pavlov, was studying digestion in dogs. Pavlov designed and surgically implanted a fistula, which allowed him to measure and analyze gastric secretions after feeding his canine test subjects. His findings from this research eventually won him a Nobel Prize in medicine, which later attributed to his prestigious standing in Russia and among the Academy of Sciences.

However, during the course of his research, Pavlov observed that some dogs started secreting enzymes before they were fed, such as when they saw the food or heard their human caretaker approaching with food. He initially saw these observations as interruptions to his original research, but finally decided to study this new phenomenon. He paired the sound of a neutral stimulus—a bell—with feeding. He would repeatedly ring the bell and then feed the dogs. Then, after a number of pairings, he’d ring the bell without feeding the dogs and measure salivary secretions. He found that the dogs then salivated at the sound of the bell. By pairing the two, he had conditioned the dog to have an involuntary physiologic response to the bell. This process is now called classical conditioning.

Ironically at the time, Pavlov saw no connection between physiological and psychological processes; however, further studies by other researchers showed that emotional responses could be conditioned too.

Edward Lee “Ted” Thorndike (1874–1949)

Around the same time, a graduate student named Edward Lee Thorndike was performing his thesis work. Thorndike made 15 puzzle boxes out of fruit and vegetable crates. He placed cats into the boxes, which had either one mechanism for escape or two. Through trial and error, the cats learned how to escape, and each time they could escape faster. Thorndike had discovered that the cats did not learn how to escape by insight or by watching others; they learned by trial and error.

From his experiments, he came up with two laws: Law of Effect and Law of Exercise.  The Law of Effect states that consequences, which are satisfying or annoying, strengthen or weaken a behavior. The Law of Exercise states that the more times an animal experiences a particular consequence, the stronger it connects it to the behavior. These laws became the basis of behavioral psychology.

John B. Watson (1878–1958): The Father of Behaviorism

Thorndike’s work provided a foundation for others to build on. One researcher who capitalized on Thorndike’s work was John B. Watson, who later became the Father of Behaviorism. In the late 1800’s and early 1900s, Watson was a psychologist at Johns Hopkins University who quickly rose to chair of the psychology department due in part to his experiments on animal learning. In these experiments, he taught rats to run mazes. At first, the rats required up to 30 minutes to complete the maze, but after 30 trials they could race through in 10 seconds. He then systematically deprived them of sensory cues, such as vision and smell. The rats were able to find their way regardless of vision or smell. He also tested this in untrained rats. He concluded that muscle sensations were the key elements in the rat’s learning process.

Later, in 1913, Watson published a paper in the Psychological Review expressing his views that animals do not learn by invisible mental processes and formulated a new psychology based entirely on observable behavior. He proclaimed that “Psychology should focus on behavior, not consciousness. Methods should be objective measures rather than introspective. It should focus on predictions and control of behavior similar to hard sciences.”  This paper formally inaugurated the Era of Behaviorism in psychology.

Watson later studied Pavlov’s conditioned reflexes but focused on emotions in infants. He found that infants have three innate emotional responses to certain stimuli—fear, rage and love. He discovered that when presented with a loud sound or suddenly being dropped, an infant displayed fear. Rage was expressed by the infant, when the arms or head were forcibly restrained and love was expressed when rocked, read stories and gently patted. He felt that all human behaviors and emotional reactions were built upon conditioned reflexes.

To attempt to prove this, he performed one of the most famous studies in history, in which he attempted to condition a fear response in an 11-month old boy they called Albert. Initially, he and his colleague placed a rat near Albert and Albert showed no fear. On a separate day, they placed Albert with the rat and, when he went to touch the rat, they hit a steel bar with a hanger behind his head, creating a loud gong. This made Albert jump, fall forward, and bury his face in the mattress. They repeated the procedure and when Albert went to do the same with the other hand he jumped, fell forward, but this time, he cried. After a week they repeated with half a dozen more pairings after which Albert had developed a full-fledged conditioned fear response to the sight of a rat. Additional experiments showed that he had generalized his fear to other furry objects such as a rabbit, a dog, a seal coat, cotton wool and even Watson sporting a Santa Claus mask. When Albert was tested several months later, he had retained this fear. Watson and his colleagues never went back to cure this association that they had classically conditioned. This type of study could never be performed under present-day research guidelines.


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