Genetic quality plays a certain role in human development and cannot be ignored. Such as intelligence level, talent, specialty and so on. , are affected by genetic quality to some extent.

Due to the differences in genetic quality, some people are easy to develop into speculative scientists, some people are easy to develop into talented musicians, and some people are easy to develop into excellent sports athletes. These differences in gene quality are usually not compensated by simple acquired efforts.

Main contributions:

1, Start the research of developmental psychology Although Hall received Feng Te's experimental psychology training at Leipzig University and set up a psychology laboratory at Johns Hopkins University after returning home, his real interest is developmental psychology research. He believes that from the point of view that psychology aims at studying human nature, the problems that experimental psychology can study are too narrow.

Therefore, he adopted the views of "adaptation" and "application" advocated by Darwin's theory of evolution and the emerging functionalism in the United States at that time, and emphasized the importance of developmental psychology.

1893, Hall pointed out in a speech at the World Military Expo in Chicago: "In the past, we all went to Europe to study psychology. From now on, we should establish American psychology; American psychology is characterized by the study of children's psychological development. "

The purpose of Hall's advocacy of children's psychological development research is not to regard developmental psychology as a pure basic scientific research, but to meet the needs of education. Hall's research on developmental psychology does not use experiments, but collects data through observation and investigation, covering children, youth and the elderly, which lays the foundation for the research orientation of developmental psychology today.

2. Advocating repetition theory to explain people's physical and mental development According to Darwin's theory of evolution, Hall put forward his repetition theory in the book Youth published in 1904, arguing that the development of individual psychology reflects the history of human development. He believes that the embryonic period before death, like tadpoles, represents the earliest period of human life in water;

The crawling in infancy represents the ape period of human evolution; The emotional instability in youth represents the chaotic period of human evolution, which was named by Holtz as the violent period of 18 century literary movement. The physical and mental maturity of adults represents the civilized period of human evolution. Hall believes that adolescent emotional instability is an inevitable phenomenon, so he advocates paying special attention to adolescent education.