Making the right decision is difficult, not least because our brains have many inbuilt biases that lead us to behave in ways that defy logic and good sense. In this extract from the New Scientist book, The Brain: A user's guide, we look at why that is and some of the most common cognitive biases to avoid.
HOW intelligent are you? When it comes to making good decisions, it doesn’t matter, because even the brightest people can do ridiculous things. Clever people act foolishly because intelligence is not the same thing as our capacity for rational thinking – and that’s what matters when it comes to making good decisions. IQ tests, designed to measure general intelligence, are very good at measuring certain cognitive abilities, such as logic and abstract reasoning. But they fail when it comes to measuring those abilities crucial to making good judgements in real life. That’s because they don’t test things such as the ability to weigh up information, or whether a person can override the intuitive cognitive biases that lead us astray. Understanding the factors that lead intelligent people to make bad decisions is shedding light on society’s biggest catastrophes. More intriguingly, it may suggest ways to evade the stupidity that plagues us all.
Gut reaction
Consider this puzzle: if it takes five machines 5 minutes to make five widgets, how many minutes would it take a hundred machines to make a hundred widgets? Most people instinctively jump to the wrong answer that "feels" right – a hundred – even if they later amend it to the correct one, which is five. When researchers put this and two similarly counterintuitive questions to thousands of students at colleges and universities – Harvard and Princeton among them – only 17 per cent got all three right. A third of the students failed to give any correct answers.
Here’s another one: Jack is looking at Anne but Anne is looking at George. Jack is married but George is not. Is a married person looking at an unmarried person? Possible answers are "yes", "no", or "cannot be determined". Most people will say it cannot be determined, simply because it is the first answer that comes to mind – but careful deduction shows the answer is "yes" (we don’t know Anne’s marital status, but either way a married person would be looking at an unmarried one).
We encounter problems like these in various guises every day. And regardless of our intelligence, we often get them wrong. Why? Probably because our brains use two different systems to process information. One is deliberative and reasoned, the other is intuitive and spontaneous. Our default mechanism is to use our intuition. This often serves us well – choosing a potential partner, for example, or in situations where you’ve had a lot of experience. But it can also trip us up, such as when our gut reactions are swayed by cognitive biases such as stereotyping or our tendency to rely too heavily on information that confirms our own.
How to be less stupid.
■ Clear your mind. Judgements are often based on information you recently had in mind, even if it’s irrelevant. For example, people bid higher at auctions when they are primed to ponder the height of the tallest person in the room.
■ Don’t fall foul of spin. We have an inclination to be influenced by the way a problem is framed. For instance, people are more likely to spend a monetary award immediately if they are told it is a bonus, compared with a rebate.
■ Use facts. Don’t allow your opinion to cloud your analysis.