Kurt Lewin conducted a study in the 1940s, analysing the effect of different types of adult leadership on groups of young boys. These are to be seen, however, as the narrator notes, as footage only for illustrative purposes and not as scientific proof.
Reference:
Lucy J A Kongola and Balaji Niwlikar. (2023, January 6). 18) Kurt Lewin: Leadership Studies. Careershodh. https://www.careershodh.com/careershodh-series-classical-experiments-18-kurt-lewin-leadership-studies/