We're all guilty of flawed thinking because our brains evolved to win others round to our point of view – whether or not our reasoning is logical

Your manipulative mind (Image: David Hollenbach)

HAVE you ever, against your better judgement, nurtured a belief in the paranormal? Or do you believe that gifted rock singers are more likely to die at the age of 27? Maybe you just have the sneaking suspicion that you are smarter, funnier and more attractive than the next person.

If you buy into any of these beliefs, you are probably suffering from confirmation bias – the mind’s tendency to pick and choose information to support our preconceptions, while ignoring a wealth of evidence to the contrary. Consider the idea that rock stars die at 27 – a fallacy that crops up time and again in the media. Once you have heard of the “27 club“, it is easy to cite a handful of examples that fit the bill – Janis Joplin, Kurt Cobain, Amy Winehouse – while forgetting the countless other musicians who survived their excesses past the age of 30.

The confirmation bias is just one of a truckload of flaws in our thinking that psychologists have steadily documented over the past few decades. Indeed, everything from your choice of cellphone to your political agenda is probably clouded by several kinds of fuzzy logic that sway the way you weigh up evidence and come to a decision.

Why did we evolve such an apparently flawed instrument? Our irrational nature is very difficult to explain if you maintain that human intelligence evolved to solve complex problems, where clear, logical thought should offer the advantage. As such, it has remained something of a puzzle.

An elegant explanation may have arrived. Hugo Mercier at the University of Neuchâtel, …