after the depression hit in 1929, popular literature began to decline while scientific publications in periodicals increased. this discrepancy between the public sector and academia supported the popular belief that professional psychologists were not interested in solving america's problems. the lack of professional participation provided pseudoscientific and unprofessional psychological literature to become very popular. in the 1930s, self-help books and the publication of three magazines ("modern psychologist", "practical psychology monthly", and "psychology digest") became part of a popular psychology movement.