Leadership has been a field of great interest for researchers and scholars for decades. Still, the second half of the 20th century saw intense interest in understanding and distinguishing leadership, both in academic circles and in practice. Over the years, leadership has been extensively researched across theoretical foundations and contexts. Leadership is generally defined by the traits, qualities, and behaviors of the leader. Leadership research has expanded across decades, different cultures, and theoretical beliefs. In contrast to Trait Theories, Behavioral Leadership Theories, and Situational Leadership Theories, which emphasize the leader's isolated function, Leader-Follower Theory focuses on the complex and significant relationship between the leader and his followers and their interconnected roles. The leader becomes a group leader who can both lead and follow. The purpose of this paper is to present previous research on transactional, transformational, and charismatic leadership, as well as servant and authentic leadership. Furthermore, the paper will provide a critical review of the levels and theoretical determinants of leadership: intra-individual, dyadic, group, and organizational processes.
Udovičić et al. (Wed,) studied this question.