Outside In | Donald Trump is a master manipulator of bias. The trouble is, we go along with it

Let’s imagine you are driving along a motorway at 80km/h. For sure, anyone driving slower than you is a senile idiot, and anyone that roars past you is a dangerous maniac. Because you have made a decision about the right speed for that particular piece of road, by definition, anyone driving faster or slower is driving inconsiderately or dangerously.

As the Financial Times’ Tim Harford observes, this is what psychologists call “naive realism” – “the seductive sense that we’re seeing the world as it truly is, without bias or error”.

“This is such a powerful illusion that whenever we meet someone whose views conflict with our own, we instinctively believe we’ve met someone who is deluded, rather than realising that we’re the ones who could learn something,” he wrote. Anyone who agrees with us is “thinking rationally” and “paying attention to facts”, while those who disagree are ignoring important facts, being “politically correct”, or seeking “peer approval”.

Harford recalls a famous 1954 study by psychologists from Princeton and Dartmouth of a football match between the two colleges. After the game, which had been more than usually violent, they took students from both colleges and asked them to count the fouls. Princeton students counted twice as many Dartmouth fouls as Dartmouth students counted – and vice versa. The researchers concluded: “Despite being shown the same footage, the students really did not see the same game.”

Daniel Kahneman concluded much the same in his brilliant Thinking, Fast and Slow: “We can be blind to the obvious, and we are also blind to our blindness.”