Which research project studuesd more than 500 children adn their parents in the 1920?

The Berkeley Longitudinal Studies was the research project studied more than 500 children and their parents in the 1920.

Explanation:

Understanding the Berkeley Longitudinal Studies

In 1920s, a research on more than 500 children alongside their parents was conducted, under the heading of the Berkeley Longitudinal Studies, to investigate the different aspects of human personality. They came to know about some of the stable characters of the human personality which were; orientation towards of humans self confidence, intellectualism, and the readiness towards accepting new ideas and experiences.