In what ways had psychology changed by the second decade of the twentieth century?
By the first 20 years in the 20th century, less that forty years when Wilhelm Wundt properly begun psychology, there was a drastic amendment in the science. Not only had the psychologists agreed on the importance of introspection, the presence of elements of mind, or the demand for psychology for remaining the pure form of science.
The progress towards functionalism was more evolutionary than revolutionary. The functionalists did not expand intentionally to damage the developments of Titchener and Wundt. They had modified it instead, by few additions such that a new kind of psychology emerges. It was more of innate than making changes outside.
The heads of the movement were not ambitious to characterize the position. They saw the task as building upon the past and not as the one breaking it. Therefore, the position in the psychology in the initial 20 years of the 20th century was that, the functionalism had begun to mature, whereas, structuralism preserved a strong, however, not an absolute position for long.
1913 carried an intentional break of both the positions along with the war. A movement of protest started which was meant to damage the previous viewpoints. Its head did not want any modifications of the previous works. This movement of revolution was known as behaviorism, promoted by Watson.