Most people agree on the qualities that a leader should have: we prefer to follow people who are confident, decisive, ambitious and persuasive rather than the insecure, dithering, apathetic and weak. So it’s not surprising that the people who possess these leadership qualities are those who seek, and often achieve, positions of power and influence.

There is, however, a dark side to power, which derives from its mind-changing effects on the people who hold it: the reluctance of subordinates to criticise or question leading to contempt for the views of others; successful outcomes of bold decisions blurring the boundaries between judgement and recklessness; personal status within an organisation generalising into a belief in “special qualities”.

The greater the power, the greater the risk of these cognitive distortions taking hold and the worse the devastation when things go wrong, as they surely must when contact with reality is lost.

An increasingly popular way of describing this pattern of behaviour is by using the term “hubris”. In ancient Greece, where it was a legal term, hubris denoted the equivalent of grievous bodily harm; in modern English hubris has come to refer to recklessness and overconfidence among those who wield power in financial or political arenas – particularly when it leads to spectacular or disastrous errors of judgement.

The behaviour of Fred Goodwin while he was CEO of the Royal Bank of Scotland and of the senior management at Enron, are popular examples from the world of finance. George W Bush’s embarrassingly premature announcement of “mission accomplished” aboard the USS Abraham Lincoln less than two months after the allied invasion of Iraq is perhaps the most celebrated example in the political sphere. What all have in common, however, is the contrast between the self-confidence of the leader and the devastating aftermath of their decisions.