“Of all the hazy and confounding areas in social psychology, leadership theory undoubtedly contends for top nomination. And, ironically, probably more has been written and less is known about leadership than about any other topic in the behavioral sciences. Always, it seems, the concept of leadership eludes us or turns up in another form to taunt us again with its slipperiness and complexity.” (Bennis, 1959, pp. 259-260)
Bennis, W.G. (1959). Leadership theory and administrative behavior: The problem of authority. Administrative Science Quarterly, 4, 259-201.