Abstract: The evaluation of nationality and social character has always been the focus of controversy between social realist and nominalist.In the more than 100 years of history of social psychology,there have been many outstanding studies on the theme of group psychology,especially David Riesman’s Lonely People.Taking the two Great revolutions around the 18th century and the consumer revolution beginning in the first half of the 20th century as the boundary stone,Riesman divided the history of the West into three periods,during which the population growth showed an S-shaped curve,specifically saying that the bottom is relatively flat,the middle is steep,and the top is gentle again,in order of “high growth potential”,“transitional growth” and “incipient decline” three stages.Accordingly,people also present three character types: traditional-direction,inner-direction and other-direction,and consumerism dominates the other-directed social character of contemporary Americans.It is worth noting that in China’s social transformation,which started slightly later but was more rapid,there seems to be a similar correlation between the population growth pattern and the transmutation of social character.