It’s graduation season, with many young people leaving the friendly confines of university life to enter the mysterious world of work.

I’ve never given a speech at a graduation but if I did I’d talk about paradox, a governing feature of life whose power sometimes takes years to fully appreciate.

This is especially true for leadership, where ignoring paradox — the contradiction between two things that can both be true at the same time — can get you into deep trouble.

Consider self-confidence. The hallmark of any great leader is the ability to convey to others that you know what’s going on and that you’re ready to take it on. Follow me, and we’ll make it work.

All you have to do is look at popular movies to see how self-confidence is such a universal characteristic of effective leadership. James Bond, Indiana Jones, and Catwoman show no fear or hesitation; instead there is certainty and confidence. And when we see managers resembling these swashbucklers, we say, ‘there’s someone who’s going places’.

If only.

Self-confidence run amok leads to mistakes and missed opportunities, whether that is taking on big acquisitions that probably should never have been made (Hewlett Packard’s deal for Autonomy, that resulted in a $8.8bn write-down), to spending too much time perfecting the old while ignoring the new (Microsoft under former CEO Steve Ballmer missing the huge revenue-generation potential of search, mobile and social media while fixating on incremental improvements in Windows).

It’s not that self-confidence is a bad thing, of course. It’s essential. But so are open-mindedness and flexibility.

Too much self-confidence means you start missing the warning signs that you might be wrong. You miss these signs because, to you, they don’t even exist. The possibility that you could be wrong is a foreign concept.

The familiarity factor

Self-confidence might also yield better results when directed toward questions or fields where you are truly expert. The corollary is even more important: open-mindedness and flexibility are critical when you’re playing a game that is unfamiliar to you. Unfortunately, such nuances barely register for the Steve Ballmers of the world.

I’ve often observed in my work with companies that while expertise in one domain usually does not transfer to other, unrelated areas, people often think that it works that way. So the CEO fancies herself an expert in technology; the professor thinks he can run the university better than the administrators; and the star athlete uses his power to force general managers to bring on players he thinks are the best.

Lest you think self-confidence is the only culprit, consider the opposite — humility. The humble but competent leader expects other people to contribute ideas, embraces the role of coach or teacher on a team, and looks for opportunities to deflect attention to others. Not only does humility leave room for stars to shine, it often leads to better thought-out decisions by drawing on the know-how of others.

All good — except that excessive humility, like excessive self-confidence, brings downsides. In many walks of life, there is no replacement for the killer instinct. Competition is all about winning, and a touch of arrogance is not such a bad thing. In a recent article in the New York Times about the NBA superstar Stephen Curry, his coach describes him as humble and arrogant. You can be both, and arguably, you need to be both.

The trick is to find the right times to exhibit either side of your leadership repertoire. Helping your teammates score is good, but so is taking charge of the game and dominating the scoring. Competition at the highest levels — in sports and in business — makes being a one-trick pony a foolish strategy.

So where does this leave us? If you’re a manager or an executive, make sure you’re not falling into the ‘more is better’ trap. Just because self-confidence is good, or humility is valuable, doesn’t mean you want to find and reward people who keep showing more of the same.

If you’re earlier in your career and trying to figure out what to work on, beware the ‘focus on your strengths’ crowd. That advice makes sense only up to a point, and that point is where management meets leadership. Work to become more aware of the limits to your leadership style. Recognise that being humble may score you points with your co-workers, but if you become typecast you’ll find it a lot harder to move up to a leadership position.

Great leaders embrace paradox. The sooner aspiring leaders understand that, the better.

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