For centuries, we’ve debated one timeless question: “Are leaders born or made?”

Since Thomas Carlyle and the Great Man Theory, the question has divided people into three categories: those who think that leaders are inherently different, better people; those who believe that leaders are tested and forged in the fires of adversity; and lastly, those who feel that both nature and nurture are essential ingredients in the recipe for leadership.

Of these three schools of thought, the most accurate may well be those who believe that leadership can be acquired.

Leadership is a skill

Leadership is a skill that anyone, in the right environment and under the right circumstances, can learn and perfect.

While many of us believe that a lucky few are born with innate leadership abilities and the necessary “talents” like confidence, creativity, and effective communication–an emerging body of research suggests otherwise. All these traits can be grown and developed through schooling and general life experience.

In a study conducted to find out the answer to this age-old question, three professors from the University of Illinois concluded that leaders are born and made on a 30/70 split. While they say 30% of leadership qualities are in genetics, they also insist that leadership can only happen in an environment that enhances it. Even with inborn abilities, simply being placed in a position of leadership like a class president doesn’t make one a leader. The professors say that great leaders must go through three stages: Readiness, willingness, and finally, ability to lead.

Show me the one “type” of leader

If all leaders were really born with that ability, then we’d have one type of leader, wouldn’t we? Researchers would be able to pinpoint the right mix of skills and spot the point of intersection between introversion and extroversion on the map where a great leader is formed.

But that hasn’t happened because there are many leaders who have completely different traits and personalities. Some leaders are introverts, while others are extroverts. Some are administrative, while others are strategic. Yet in the end, they are all great men and women, and they all achieve success–in their various fields.

For instance, Abraham Lincoln, Martin Luther King, Jr., Nelson Mandela, Maya Angelou, Eleanor Roosevelt, Steve Jobs, Bill Gates, Mark Zuckerberg, and Warren Buffett all were (and are) great leaders. They each succeeded in their own sphere, whether it be business, politics, humanitarianism, or literature. But putting them all in a classroom and giving an exam on “Best Leadership Style” would be unfair. Each have unique strategies and paradigms for leadership.

Emotional Intelligence (EI) is at the center of great leadership

Through its Global Learning Institute, FedEx Express is “building the skills and expertise for people-first leadership.” A 2014 case study showed that the program was “yielding an 8-11% increase in core leadership competencies.”

Through the PSP Philosophy, FedEx Express has demonstrated the role Emotional Intelligence (EI) plays in leadership. And it’s determined to cultivate EI in order to improve internal leadership.

The greatest leaders have a combination of skills such as self-awareness and regulation, self-motivation, social skills, and empathy. It can’t be argued any other way: These skills are absolutely essential to effective leadership. But are these the skills one is born with?

Absolutely not.

In fact, they are learned every day through real-life relationships with other people. Meaning, they can be improved or stunted. Thus, the difference between a great leader and an average one largely hinges on EI, all factors considered.

Just like any other skill, EI is a learned skill set. And it’s at the cornerstone of great leadership.

Certain experiences spark leadership

Rarely do people become leaders without first experiencing intense, transformative experiences that act as catalysts for their change in perception and behavior.

Think Nelson Mandela, Martin Luther King Jr, Abraham Lincoln or any other leader and there’s a strong possibility that you’ll identify a situation that might have catapulted anyone to that position of leadership.

“But why them and not anyone else?” one might ask. And that’s where the learned EI skills come in. Without sufficient self-awareness and motivation, for instance, one cannot willingly rise into that position. Without people around that one can work with, a leader cannot be effective in their role.

Leadership is about nurture, not nature

The American Psychological Association published a study that found that given the dynamic and complex social environments in which most leaders operate, effectiveness requires them to possess certain perceptive and adaptive capabilities. Thus, these qualities don’t just appear and they certainly don’t develop in a vacuum. Such traits have to be nurtured, and when they are, they form the grid of components that researchers have called Complexity Leadership. It explains how great leaders evolve and grow into their positions in the society and history.

So, yes, the documentary will always try to make it look like your mentor was a leader right from the start. But the truth is quite the opposite: they were forged into the leader they are today. Through schooling, human interaction, and undergoing life experiences that impacted their perspective and behavior, the leader was made. And they continued to cultivate that skill even after stepping into their position.

Ultimately, that is the path a leader must take.