G. Stanley Hall is credited with founding psychology as a research science and a profession. Known also as the father of the child study movement in America, he was born in the western Massachusetts hill town of Ashfield. His parents were deeply religious farmers who struggled to make ends meet.

Like most children in antebellum Massachusetts, G. Stanley Hall attended the local district school. When he proved to be a gifted student, his parents managed to send him on to local academies where he could prepare for college.

In 1863 he entered Williams College, where many students were training for the Congregational ministry. During his sophomore year, Hall participated in a revival at the college and became a committed Christian.

To his parents' great joy, he began teaching a Bible class for workers in a nearby factory village and made plans to enter seminary upon graduation. In 1867 he enrolled at Union Theological Seminary in New York. Hall's professors noticed almost immediately that the young man had strong skeptical tendencies. These led Hall to quit the seminary and travel to Germany. He spent the next two years studying German, theology, and philosophy.

By 1871 Hall was deeply in debt. He returned to the U.S, completed his theological studies, and found a teaching post at Antioch College in Ohio. A book he read in 1874 introduced him to the new science of psychology. In 1876 he enrolled at Harvard and two years later earned the very first American Ph.D. awarded in the field. Hall focused his work on using psychology to explain how children develop and learn.

His first job teaching psychology was at Johns Hopkins University in Baltimore, where he stayed for seven years. In 1887 he founded the American Journal of Psychology and four years later the American Psychological Association.

In 1887 a new university devoted to scientific research opened in Worcester. The trustees named G. Stanley Hall the first president of Clark and charged him with creating a school modeled on Germany's scientific research centers. Among his students were men who would dominate American psychology for the next few decades.

In 1909 G. Stanley Hall organized an international conference at Clark. He brought together 175 of the world's leading psychologists, including Carl Jung and Sigmund Freud, and an assortment of educators, physicians, and "the odd political revolutionary" in the person of Emma Goldman. Freud's five lectures at Clark (given in German over the course of five days) were the only ones he ever gave in the United States, and the honorary degree he received was the only one ever bestowed on the father of psychoanalysis.

Hall's own work focused on the nature of child development. He devoted himself to the new child study movement. Believing that each individual's growth follows the evolutionary pattern of human development, he formulated educational recommendations for the different stages of childhood. There was considerable popular interest in his research; magazines disseminated his theories to the general public.

Over the course of his career, Hall lectured widely at Clark and beyond. He read extensively and published prolifically. 

Hall resigned the presidency of Clark in 1919 after a 30-year tenure. In retirement, he returned to his early interests in philosophy and religion. He died in 1924 at the age of 80. In a tribute to Hall held by the National Academy of Science held the year after his death, a colleague described him as follows: "Dr. Hall started more lines of new thought and set more persons to thinking that any other person in all history. Some others have been more methodical, have developed more refined technique, and have been better text book makers. But no other one has had so much vision. . . . He is the Edison of psychology."