Humour and charm are a surprisingly powerful combination as a means of ascent in life.

I have met a number of entrepreneurs who have built fortunes on the back of their wit and general popularity – and not much else. They disarm us with self-deprecation, we enjoy their company – so why wouldn't we want to do business with them? Of course, it all has to be done well; sycophancy and flat jokes do not weave the same spell.

The British feel that some light relief amid the drudgery is essential for existence to be tolerable. It seems to be a cornerstone of our psychology and culture. In London, to say someone has no sense of humour is to condemn them utterly. Many important meetings I attend start with a little friendly banter to break the ice, a ritual to remind us that we are all human – rather than simply robots of commerce.

I am sure foreigners must think our levity is baffling. My defence is that Brits subscribe to Horace's view: “A jest often decides matters of importance more effectively and happily than seriousness.”

Some years ago, a partner of mine practised what I called “management by laughter”. He motivated and inspired by making the atmosphere at work fun, rather than the bullying and intimidation common in many workplaces.

But the 21st-century office can be a minefield for the amateur who enjoys a giggle. I was recently warned about a trap being sprung by a professional gang from eastern Europe. They plant an attractive female staff member in an organisation. At roughly the same time, a male co-conspirator also gets a job; the connection between them is unknown to the employer. After a little while, he sends a series of highly suggestive internet jokes to the pretty female. She complains of harassment and threatens to bring an embarrassing employment tribunal involving sexual discrimination – and, once she reveals that she has hired expert legal advisers and PR agents, the victim business settles quickly.

In these litigious, politically correct times, the perils of making cheap gags can be considerable. Recently, I attended a dinner at a trade conference. The speaker was a well-known executive who told a number of jokes in poor taste, some at the expense of influential figures in the room. Just as a vulgar best man's speech at a wedding can strike the wrong note, so I sensed as we chatted after the speech that the jibes would not be swiftly forgotten.

Someone once said: “Brains, integrity and force may be all very well, but what you need today is charm.” This is the age of celebrity, even in the boardroom, and none of us is impervious to the presence of those legendary characters when they switch on the full blast of their glittering personality. Perhaps it is their reputation, perhaps their smile, perhaps their brilliance with words – or possibly their rapt attention.

I am often struck how often young children utter the phrase “Look at me!” They want appreciation, and fundamentally not much changes, even when we are 50. Genuine approval from the boss can taste better than anything – even a pay rise.

Are charm and a sense of humour acquired traits? They certainly improve with effort and practice. Ronald Reagan used his years in showbiz to hone his performance skills before succeeding in politics.

I have sat with stand-up comics before they go on stage. The most brilliant appear almost nonchalant, rather than rehearsed or anxious, and their acts are mostly learnt word-perfect yet appear spontaneous.

So it is with outstanding business leaders who persuade their teams to laugh and try harder: they apply themselves assiduously to the task. Most world-class chief executives possess charisma – really a captivating blend of charm and wit. And, believe me, they graft at it far more than they admit.