On paper, we would always say that politics comes ahead of presentation. But is this always the case?

In 1960, 66 million Americans watched the first ever televised presidential election debates in which Kennedy and Nixon locked horns. Such debates are now the cornerstone of heavily published campaign trails and can make or break a presidential candidate.

In the lead up to the next general election, Gordon Brown, David Cameron and Nick Clegg will go head-to-head in a series of televised debates, the first of their kind in Britain. However, television can be a fickle friend: on the one hand, it allows politicians to figuratively 'kiss the baby's head' in every living room; yet on the other hand it can damn a candidate to a life-time of cringe-worthy re-runs on YouTube. So what are the lessons to be learnt from the history of televised debates, and particularly the psychology of appearance?

Let's take the Kennedy-Nixon debates. Kennedy's camp had been successful in preparing their man for the cameras. He was tanned and looked vibrant. Nixon, on the other hand, looked dour, frail and sweaty.

Following the debate, a commercial research firm surveyed listeners and viewers asking which candidate had won. Interestingly, they found that television viewers gave Kennedy the edge, while radio listeners preferred Nixon, despite the fact that, in substance, both candidates were closely matched. For TV viewers, it's probable that the power of appearance meant that style won over substance.

And the psychology? Basically, we are pretty awful at making objective decisions that exclude irrelevant data - such as attractiveness, height, dress sense, or whether someone has a nice tan and set of pearly-whites. To illustrate this point, consider these findings from psychological research.

It is well proven that initial impressions are powerful. When we see someone or something, we typically take around two seconds to form an unconscious judgement. Following this judgement, we then try to confirm this initial impression. Whilst such intuition can at times be accurate, it is also be significantly influenced by our own biases and prejudices.

As an example, height does not correlate with intelligence, judgement skills or ability to lead and motivate others. Anyone who, in the cold light of day, would argue that it does is likely to be treated with contempt. However, psychologists again have demonstrated that there is a correlation between height and seniority (read: success) within organisations. If height has nothing to do with the characteristics needed to be successful, then biases related to appearance must be a significant influencer.

Likewise, in court rooms, psychologists have persuasively shown that 'attractive' defendants are perceived as more credible, are acquitted more often and receive lighter sentences than less attractive counterparts.

In essence, we make quick and fairly basic decisions, typically subconsciously, in order to make sense of an incredibly complex world. However, our biases can play an equally significant role in clouding our judgement.

So what? Well of course Brown, Cameron and Clegg will be working hard to manage their appearance in the coming weeks - they have a team of advisors doing just that. The real issue lies with you, the voter. This is a simple but important reminder to be alert and wary of the power of appearance. Watch out for the tricks, the polish and the purple ties. And then listen to the real issues.

I, for one, will be trying to ignore that Brown looks like a sour-puss, Cameron looks like a toff and Clegg looks like...well...actually, what does he look like? No problem there then.