Leadership - Are leaders born or made?

Leadership - Hollander in 1985 described it as "The process of influence between a leader and followers to attain group organisation or social goals".
Are leaders born or made? In this essay I hope to investigate this question using studies and theories on the subject. By the end of the essay I should be able to draw an informed conclusion to this answer from my perspective.

The emergence of leaders.

When discussing leadership, there are two main theories that can be adopted. Firstly, there is the situational approach, which is unsurprisingly concerned with the situation. There may, for example, be a person within a business environment whom is tasked with controlling and leading a group of colleagues. It is therefore when the leadership task is viewed as a conscience process i.e. "I have been tasked as leader, I must lead the group".
Alternatively, the theory of the trait approach is where the individual does not assume the role as leader consciencely, or put another way, they are born as a natural leaders and will often assume the role of leader in an anonymous situation, already possessing the correct qualities for the position.

The Trait approach studies.

It was once attempted to try and determine what qualities were most common in someone thought to be a natural leader. In the test, a number of characteristics were proposed as being advantageous, these were height, weight, appearance and intelligence. Further studies by Gibb in 1969 suggest that the typical leader is only slightly more intelligent than the average group leader. Gibb also concluded that leaders are neither predominantly authoritarian nor equalitarian, but an equilibrium between the two. It resulted that the findings were not conclusive and that leaders do not consistently possess the same particular types of characteristics as each other, furthermore, they do not always possess entirely different characteristics to those of the non-leaders i.e. the group members. The difficulty to come to a precise conclusion was such that many psychologists gave up trying to find the answer. Research in more recent years in a business environment has found that leaders do differ from group members, or at least more conclusively than Gibb in 1969.
In 1991, Kirkpatrick and Locke identified that flexibility was a key trait in the leader's personality, this is probably because the leader must be able to balance the wishes of group members, and grant them concessions in order for them to complete their given role within the group. Other significant traits which were found in leaders included knowledge of the relevant subject and a trust in their own abilities, these equate to one factor - CONFIDENCE. According then to Kirkpatrick and Locke, leaders are distinguished from others by having a mixture of personal attributes more biased to the qualities that make a leader, or as Kirkpatrick and Locke put it, 'The right stuff'.

A different approach was taken by Bales and Slater in 1955. They observed discussions of tasks between group members and leaders and identified two types of leaders. The first was the task specialist leader, who was mainly concerned with the group achieving a common goal, this was summed up well in Yukl's definition of leadership in 1989, "the process through which one member of a group (i.e. it's leader) influences other group members towards the attainment of a common group goal". Secondly, there was the socio-emotional specialist who was primarily concerned with the inter-group relationships. It was thought that these two different styles would compliment each other when applied at once. It was eventually concluded that the success of a particular style would depend strongly on the nature of the group and the task that was being undertaken.

An early study of leadership and it's effectiveness was conducted by Lewin et al. (1939). In their study, they investigated the effect of three different styles of leadership on a group of ten year old boys attending an after school model making group.
The first leader was briefed to take a democratic approach to his leadership style, he had to express an interest and discuss activities with the boys. The results showed that the boys were more satisfied, organised and independent than the other two groups.
The second group had an autocratic leader who was