Trait theories argue that effective leaders share common personality traits or characteristics. These include traits and qualities such as integrity, honesty, assertiveness, decisiveness, motivation, innovation, vision, intelligence, persuasiveness, etc. Early trait theories posed that leadership traits are innate and that one is born to be a leader. Trait theories have now evolved and pose that one can learn leadership traits, and that positive leadership traits can be developed through training and education. Many studies on leadership traits have been conducted in an attempt to identify traits of successful leaders. The Forbes top 10 qualities that make a great leader include: honesty, creativity, intuition, confidence, commitment, ability to inspire, delegate, and communicate, a sense of humor, and positive attitude [1]. While many of the above traits are associated with great leaders, it should be noted that the converse does not necessarily hold true, i.e. that having these traits or a combination of these traits guarantees that one will be a successful leader. Chapter 5 in this textbook explores leadership trait theories in-depth as well as some of the common traits of successful leaders.

Behavioral theories focus on how a leader behaves. In the early 1930s, Kurt Lewin presented a framework based on the behaviors of leaders [2]. He described three types of leadership behaviors: (1) autocratic; (2) democratic; and (3) laissez-faire. Autocratic leaders are described as making decisions without consulting their teams. This type of leadership is appropriate when quick decisions need to be made, when there is no need for agreement, or when agreement from the team is not necessary in order for a successful outcome to be achieved. Democratic leaders take into consideration input from the team before making a decision. The degree of input considered will vary from leader to leader. This type of leadership is appropriate when team agreement is important for the final outcome. However, this style of leadership can be difficult to manage when a wide variety of opinions, perspectives, and ideas exist among the team members. Laissez-faire leaders typically do not interfere with the decision-making process. These leaders allow the individuals in the team to make most of the decisions. This type of leadership is appropriate when the teams consist of highly competent, skilled, motivated and capable individuals that require little supervision. This leadership style can fail when it is born out of laziness on the part of the leader. Since the description of these three leadership styles, many more styles have emerged. A description of the most common leadership styles follows below.

Contingency or situational leadership theories pose that no one leadership style is the correct style. Instead, the best leadership style is the one dictated by the situation or circumstance (i.e., situational leadership). For example, if a quick decision is required, the autocratic leadership style might be best. If the full support of all team members is required, the democratic leadership style might be best. Contingent leadership theories also pose that the best leadership style depends on characteristics of the team members. For instance, the Hersey-Blanchard Situational Leadership Theory proposes that successful leaders should change their leadership styles based on the maturity of the people on the team and the details of the task [3]. Hersey and Blanchard describe four leadership styles for this theory (i.e., telling, selling, participating, and delegating) and four maturity levels. The use of each style is dictated by the maturity level of the team members. If the team members have a low maturity, the telling style works best. If the team members have high maturity, the delegating style works best. The Dunham and Pierce Leadership Process Model describes how four factors contribute to leadership success or failure [4]. These factors are: the leader, the followers, the context, and the outcome. All four variables are related to each other and affect each other. This model highlights that leadership is dynamic and that it is important to be flexible based on the context, the outcome, and the team.

Power and influence theories are based on the different ways in which leaders use their power and influence to get things done. These theories then examine the leadership styles that emerge as a result. For example, people tend to follow others who are powerful. When others follow that person, the person with power leads. But, there are different reasons why people have power. One of the best-known theories that describes this type of leadership is French and Raven’s Five Forms of Power [5]. John French and Bertram Raven described five forms of power: legitimate, reward, expert, referent, and coercive. Legitimate power comes from the belief that that person has the right to make demands and expect compliance, such as a CEO or president. Reward power is when someone has the power to compensate others for their actions (i.e., salary increase, bonus, etc.). Expert power comes from a person’s own superior skill or knowledge (i.e., recognized expertise). Referent power results from a person’s perceived worthiness, charm, charisma, or appeal, such as celebrities. Coercive power results when someone has the ability to punish others. When a person recognizes their source of power they are better able to lead for the best outcome. The positional power sources (i.e., legitimate, reward, and coercive) tend to be the least effective as they can easily fail, while the personal power sources (i.e., expert and referent) tend to be the most effective.

Emotional intelligence is having the ability to understand and manage your emotions as well as those of the people around you (direct reports, peers, and supervisors). Leaders with emotional intelligence tend to be calm, don’t lose their temper, and don’t get out of control, no matter what the situation or crisis is about. Leaders with emotional intelligence are able to recognize what they are feeling, what these emotions mean, how these emotions can impact others, and are able to modulate their leadership style based on this information. Having emotional intelligence is essential for a leader. First popularized by Daniel Goleman, five elements of emotional intelligence have been described: (1) self-awareness; (2) self-regulation; (3) motivation; (4) empathy; and (5) social skills [6]. The more a leader is able to understand how their emotions and actions impact others and is able to manage each of these five elements, the higher the emotional intelligence. The higher the emotional intelligence, the more successful he or she will be as a leader, as they will be able to relate to and work with others better. To learn more about emotional intelligence and these five elements, the reader is directed to Chap. 6 on emotional intelligence written by Drs. Harry Sax and Bruce Gewertz.