Final answer:
Stanley Hall initiated the child study movement and significantly contributed to the field of developmental psychology. He established the first American psychology laboratory and was the founding president of the American Psychological Association.
Step-by-step explanation:
Stanley Hall is widely recognized as a pioneering figure in psychology, often credited with initiating the child study movement. He was also instrumental in the establishment of developmental psychology as a distinct academic discipline. In 1883, Hall received the first Ph.D. in psychology in America, studied under Wilhelm Wundt in Germany, and went on to influence the field significantly. He is perhaps best known for his work on adolescence and the concept of "Storm and Stress" associated with this developmental stage.
Furthermore, Hall founded the first American psychology laboratory at Johns Hopkins University and was the first president of Clark University where he worked until his death. His influence extended into education reform and he was also the founding president of the American Psychological Association (APA), emphasizing his impact on the field.