I define charisma as an authentic power that captivates the hearts and minds of others. To put it another way, when you are being you, and you love what you do – you shine. This definition begins to explain why charisma is contextual.

The charismatic individual who shines in a career context can be almost invisible in a social or home environment. A performer or a politician may dazzle when they are in the public eye, because what they are doing is important to them. Put them in another setting and they merge to become one of the crowd.

If the late Martin Luther King was asked to deliver a speech on boxing, would his passion, authenticity and charisma have shone through in the same way? This definition differs from the stereotypical view in two key ways. I do not believe that an extrovert or having a ‘big personality’ is a pre-requisite to being charismatic. On the contrary. The single most important factor that determines an individual’s charisma is the extent that they are able to ‘captivate hearts and minds’. Often you’ll find that quietly confident, introverted people are every bit as charismatic as their more self-publicising counterparts.

This view is supported by a study reported in Business Week showing that a more reserved style of introverted leaders can actually inspire better performance in followers. Researchers Adam Grant of the Wharton School, Francesca Gino of Harvard Business School, and David Hofmann at the University of North Carolina found that if the employees are an extroverted, proactive bunch by nature, the team will perform better under the leadership of an introvert than under an extrovert. The study goes on to explain that introverted leaders are more likely to take a team approach to problem-solving and to let talented team members spread their wings.

I am sure that we can all think back to leaders, managers, teachers or mentors who have patiently drawn out our opinions, encouraged our creativity and have genuinely valued and shown appreciation for our contributions to the achievement of a collective goal. These people may not all have met the regulation blueprint of a charismatic leader, but they managed to ‘captivate our hearts and minds’ none-the-less.

When we think of charismatic and introverted people who have had enormous impact on the world – there are many examples. Mahatma Ghandi, Meryl Streep, Steve Jobs, Albert Einstein, Princess Diana and even Robbie Williams, often showed a quiet vulnerability that somewhat disproves the claim that you need to be an extrovert to be charismatic.

The key to charisma is authenticity. One of the most exciting television projects I did was as an Official Political Commentator for Aljazeera during the 2010 live UK election debates. This project stands out because it was the first time that political leaders engaged in a live televised debate. Working with the Professor of British Politics (who was required to commentate on the leaders’ policies), my role was to commentate on their authenticity and charisma.

I remember watching Gordon Brown as his insecurities around being pitted against his two younger adversaries were demonstrated in the form of aggressive and often rude behaviour. Shortly afterwards I watched the then Labour party leader give a resignation speech that he had written himself. As he spoke from his heart, his warmth and ‘humanness’ shone through and I wondered why he had not just been himself during ‘The Lives’.

In business, as in politics, alarm bells start to ring when a leader’s ‘from the heart’ emotional response seems a bit too coached. I remember watching Tony Blair in 1997 as he announced the death of Princess Diana. I was filled with a sense that he was delivering a brilliant speech designed to tug at our heart strings. It felt a bit too contrived. When the words just don’t match with the body-language, and especially when our hard-wired unconscious mind feels that there is something less than authentic about them, we will experience a negative reaction that we often can’t quite explain logically.

This may well be why we love our sporting heroes to be charismatic in the absolute stereotypical –big, brash, confident, sense of the word! When Muhammad Ali, with absolute unshakeable self-confidence, stared down the camera and stated that he was ‘The Greatest’, we believed him, and we didn’t start looking for any hidden agendas, because there were none.

I would go as far as to say that we expect our sporting heroes self-esteem to be developed close to the point of arrogance, otherwise it just doesn’t seem authentic. Unconsciously we question whether they have that all -important ‘will to win’. Andy Murray won more fans for losing to Federer at Wimbledon in 2012, and letting us see just how much that loss hurt him, than he did by reversing the result several weeks later at The Olympics.

Conversely, because we have a fundamental belief that politicians are – first and foremost – public servants, for us to see them as authentic, (and therefore charismatic), we need them to show far more humility than our ego driven sporting heroes. Our Political Leaders draw their charismatic appeal not from their displays of confidence or self-esteem, but from their vision, driving force and devotion to their mission or purpose.

We believed in Nelson Mandela because he showed us, with his suffering and sacrifice, that he really cared. Nobody could ever doubt that Ghandi wasn’t passionate about the plight of his people, or that Martin Luther King had a dream that became more real than his harsh reality.

In business, the leaders that we recognise as being truly charismatic have the ability to walk that fine line between letting us see that they possess huge drive to be successful, whilst at the same time, demonstrating an appreciation and understanding of their ethical and social responsibilities.

The really interesting thing is that, in business, as in politics and sport, at the point when a charismatic leader ceases to be authentic, at the moment when he or she fails to connect at an emotional level, their charisma is lost, and the spell is broken. If an individual lacks authenticity, if they don’t mean what they say, they dilute the strength of their character and consequently the strength of their charisma.

Some individuals compensate for their lack of internal and external congruency by over developing their external charm. If you try to emulate any other charismatic individual you are effectively acting and wearing a mask of charisma. Whatever external mask you choose to wear, if it doesn’t reflect the genuine, authentic ‘you’ it will automatically convey a superficial aspect to your personality. The only way to be truly charismatic is to be authentic and speak from your heart.