He largely conducted research on three topics: attitude change in the context of inter-group relations, minority group identification, and opiate addiction in juveniles.
[2] In addition, Chein served as a research associate of New York City Mayor Fiorello La Guardia’s Committee on Unity.
[3] As a member of Mayor La Guardia's administration, Chein worked on social problems affecting New York City.
Chein served as the director of research for the Commission on Community Interrelations of the American Jewish Congress, vice president of the Psychological Service Center of the New York Society of Clinical Psychologists, and president of the Society for the Psychological Study of Social Issues.
[1] In addition, Chein contributed to the making of the Supreme Court's 1954 decision in Brown v. Board of Education.
Chein, Stuart W. Cook, and Kenneth B. Clark co-wrote the amicus curiae brief (also known as "the social scientists' brief") for the purpose of acquainting the justices with the impact segregation had on the psychological functioning of African American children.
His work on the objective environment, however, was important to his research efforts in the next area: the psychology of opiate addiction in juveniles.
He believed that a total environment devoted to treating addiction, including sheltered employment, protected living quarters, and sometimes surrogate parents, was needed.
Chein regarded the human being as "an active, responsible agent, not simply a helpless, powerless reagent.
[2] The next year, the Society for the Psychological Study of Social Issues presented Chein with the Kurt Lewin Memorial Award.