Leadership has been described as “a process of social influence in which a person can enlist the aid and support of others in the accomplishment of a common task”.[1] For example, some understand a leader simply as somebody whom people follow, or as somebody who guides or directs others,[citation needed] while others define leadership as “organizing a group of people to achieve a common goal”.

A summit meeting (or just summit) is a meeting of heads of state or government, usually with considerable media exposure, tight security, and a prearranged agenda. Notable summit meetings include those of Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin during World War II. However, the term summit was not commonly used for such meetings until the Geneva Summit (1955).[1] During the Cold War, when American presidents joined with Soviet or Chinese counterparts for one-on-one meetings, the media labelled the event as a “summit”. The post-Cold War era has produced an increase in the number of “summit” events. Nowadays, international summits are the most common expression for global governance.

Studies of leadership have produced theories involving traits,[2] situational interaction, function, behavior, power, vision and values,[3] charisma, and intelligence, among others.

Theories
Early western history[edit]
The search for the characteristics or traits of leaders has continued for centuries. Philosophical writings from Plato’s Republic[4] to Plutarch’s Lives have explored the question “What qualities distinguish an individual as a leader?” Underlying this search was the early recognition of the importance of leadership[citation needed] and the assumption that leadership is rooted in the characteristics that certain individuals possess. This idea that leadership is based on individual attributes is known as the “trait theory of leadership”.

A number of works in the 19th century – when the traditional authority of monarchs, lords and bishops had begun to wane – explored the trait theory at length: note especially the writings of Thomas Carlyle and of Francis Galton, whose works have prompted decades of research. In Heroes and Hero Worship (1841), Carlyle identified the talents, skills, and physical characteristics of men who rose to power. Galton’s Hereditary Genius (1869) examined leadership qualities in the families of powerful men. After showing that the numbers of eminent relatives dropped off when his focus moved from first-degree to second-degree relatives, Galton concluded that leadership was inherited. In other words, leaders were born, not developed. Both of these notable works lent great initial support for the notion that leadership is rooted in characteristics of a leader.

Cecil Rhodes (1853-1902) believed that public-spirited leadership could be nurtured by identifying young people with “moral force of character and instincts to lead”, and educating them in contexts (such as the collegiate environment of the University of Oxford which further developed such characteristics. International networks of such leaders could help to promote international understanding and help “render war impossible”. This vision of leadership underlay the creation of the Rhodes Scholarships, which have helped to shape notions of leadership since their creation in 1903.[5]

Rise of alternative theories[edit]
In the late 1940s and early 1950s, however, a series of qualitative reviews of these studies (e.g., Bird, 1940;[6] Stogdill, 1948;[7] Mann, 1959[8]) prompted researchers to take a drastically different view of the driving forces behind leadership. In reviewing the extant literature, Stogdill and Mann found that while some traits were common across a number of studies, the overall evidence suggested that persons who are leaders in one situation may not necessarily be leaders in other situations. Subsequently, leadership was no longer characterized as an enduring individual trait, as situational approaches (see alternative leadership theories below) posited that individuals can be effective in certain situations, but not others. The focus then shifted away from traits of leaders to an investigation of the leader behaviors that were effective. This approach dominated much of the leadership theory and research for the next few decades.

Reemergence of trait theory[edit]
New methods and measurements were developed after these influential reviews that would ultimately reestablish the trait theory as a viable approach to the study of leadership. For example, improvements in researchers’ use of the round robin research design methodology allowed researchers to see that individuals can and do emerge as leaders across a variety of situations and tasks.[9] Additionally, during the 1980s statistical advances allowed researchers to conduct meta-analyses, in which they could quantitatively analyze and summarize the findings from a wide array of studies. This advent allowed trait theorists to create a comprehensive picture of previous leadership research rather than rely on the qualitative reviews of the past. Equipped with new methods, leadership researchers revealed the following:

Individuals can and do emerge as leaders across a variety of situations and tasks.[9]
Significant relationships exist between leadership emergence and such individual traits as:
Intelligence[10]
Adjustment[10]
Extraversion[10]
Conscientiousness[11][12][13]
Openness to experience[12][14]
General self-efficacy[15][16]
While the trait theory of leadership has certainly regained popularity, its reemergence has not been accompanied by a corresponding increase in sophisticated conceptual frameworks.[17]

Specifically, Zaccaro (2007)[17] noted that trait theories still:

Focus on a small set of individual attributes such as Big Five personality traits, to the neglect of cognitive abilities, motives, values, social skills, expertise, and problem-solving skills.
Fail to consider patterns or integrations of multiple attributes.
Do not distinguish between those leader attributes that are generally not malleable over time and those that are shaped by, and bound to, situational influences.
Do not consider how stable leader attributes account for the behavioral diversity necessary for effective leadership.
Attribute pattern approach[edit]
Considering the criticisms of the trait theory outlined above, several researchers have begun to adopt a different perspective of leader individual differences—the leader attribute pattern approach.[16][18][19][20][21] In contrast to the traditional approach, the leader attribute pattern approach is based on theorists’ arguments that the influence of individual characteristics on outcomes is best understood by considering the person as an integrated totality rather than a summation of individual variables.[20][22] In other words, the leader attribute pattern approach argues that integrated constellations or combinations of individual differences may explain substantial variance in both leader emergence and leader effectiveness beyond that explained by single attributes, or by additive combinations of multiple attributes.

Behavioral and style theories[edit]
Main article: Managerial grid model
In response to the early criticisms of the trait approach, theorists began to research leadership as a set of behaviors, evaluating the behavior of successful leaders, determining a behavior taxonomy, and identifying broad leadership styles.[23] David McClelland, for example, posited that leadership takes a strong personality with a well-developed positive ego. To lead, self-confidence and high self-esteem are useful, perhaps even essential.[24]
A graphical representation of the managerial grid model
Kurt Lewin, Ronald Lipitt, and Ralph White developed in 1939 the seminal work on the influence of leadership styles and performance. The researchers evaluated the performance of groups of eleven-year-old boys under different types of work climate. In each, the leader exercised his influence regarding the type of group decision making, praise and criticism (feedback), and the management of the group tasks (project management) according to three styles: authoritarian, democratic, and laissez-faire.[25]

The managerial grid model is also based on a behavioral theory. The model was developed by Robert Blake and Jane Mouton in 1964 and suggests five different leadership styles, based on the leaders’ concern for people and their concern for goal achievement.[26]

Positive reinforcement[edit]
B.F. Skinner is the father of behavior modification and developed the concept of positive reinforcement. Positive reinforcement occurs when a positive stimulus is presented in response to a behavior, increasing the likelihood of that behavior in the future.[27] The following is an example of how positive reinforcement can be used in a business setting. Assume praise is a positive reinforcer for a particular employee. This employee does not show up to work on time every day. The manager of this employee decides to praise the employee for showing up on time every day the employee actually shows up to work on time. As a result, the employee comes to work on time more often because the employee likes to be praised. In this example, praise (the stimulus) is a positive reinforcer for this employee because the employee arrives at work on time (the behavior) more frequently after being praised for showing up to work on time.

The use of positive reinforcement is a successful and growing technique used by leaders to motivate and attain desired behaviors from subordinates. Organizations such as Frito-Lay, 3M, Goodrich, Michigan Bell, and Emery Air Freight have all used reinforcement to increase productivity.[28] Empirical research covering the last 20 years suggests that reinforcement theory has a 17 percent increase in performance. Additionally, many reinforcement techniques such as the use of praise are inexpensive, providing higher performance for lower costs.