hinking, Fast and Slow by Daniel Kahneman was published in 2011. It became a bestseller and changed the way that many people thought about economics and human reason. Although Kahneman based the book on his own research, the core ideas behind Thinking, Fast and Slow had been around for decades. So what are these two types of thinking and why are they important for you to understand?
For as long as people have speculated about the way the mind works, there have been theories about different ways of thinking. Some of these ideas still persist today, such as the stereotype that women are more intuitive, while men are more logical. In the 1970s, psychologists talked about "dual process theory," although rather than classifying thought as intuitive and logical, they described it as heuristic and analytic. In this context, a heuristic is a mental shortcut, a way of making a decision without needing to do lots of complex analysis. Heuristic thinking is fast, while analytic thinking is slow.
Now psychologists call these two ways of thinking Type 1 and Type 2. Type 1 is fast thinking; it enables you to make decisions quickly. Type 2, or slow thinking, takes more time and, crucially, uses more resources in the brain. This difference in resource use helps to explain why two separate ways of reasoning have evolved. Type 2 is usually more accurate; it involves thinking through different variables and making a conclusion based on evidence. The downside of this is that it uses more energy in the brain; Type 2 reasoning is literally hard work for your mind. On the other hand, Type 1 uses much less energy, but is more likely to make mistakes. As the human brain evolved, there was a need for fast, energy-efficient thinking, but humans gained an advantage over other species (and other humans) if they could do complex reasoning too. This is why today you have a brain that thinks in two different ways.
Thinking in two different ways explains why you can have a gut reaction to somebody you've just met, even if you know almost nothing about them.
Often people who are applying for a job are warned that an interviewer will make up their mind in the first few seconds. This isn't always the case and initial impressions can be changed, but it's certainly true that when you first meet someone you'll use Type 1 thinking to make a judgement about them. Because Type 1 thinking is automatic and closely related to your emotions, you experience a gut feeling; you like or dislike someone without really knowing why. Everybody does this to a certain extent, but luckily Type 2 thinking can override Type 1. Actually getting to know someone can mean that you change your mind about them. This is important for your ability to make connections with a variety of different people. Unless you use slower Type 2 thinking and get to know someone, you could be missing out on an important relationship.
Type 1 reasoning is also related to errors in thinking known as cognitive biases. There are hundreds of these, and many of them are related to fast thinking. For example, more people would choose a medical procedure with a 90% success rate than one with a 10% failure rate. Type 2 thinking can see that these are exactly the same, but Type 1 thinking prefers the high probability of success over the small chance of failure. This kind of bias, known as a framing error, is used all the time by advertisers and salespeople in order to push you into a Type 1 decision. Taking the time and effort to analyse a decision will enable Type 2 thinking instead. This is why so many special offers are described as short-term or with limited availability. Advertisers don't want you to take the time to use slower Type 2 reasoning.
Fast thinking has also been linked with anxiety. When you're feeling anxious, your Type 1 reasoning is working closely with your emotions.
It happens automatically, which is why people describe anxiety as hitting them out of the blue. And although simply thinking through an anxiety-provoking situation won't necessarily solve your problems or change your brain chemistry, there's anecdotal evidence that taking time to think things through is a powerful antidote to anxiety. Cognitive Behavioural Therapy (CBT), one of the most common treatments for anxiety, is a classic example of using Type 2 reasoning.
Fast and slow thinking describes what psychologists call Type 1 and Type 2 reasoning. Type 1 is fast, efficient and tends to be your brain's first response to a situation, but is prone to error. Type 2 takes longer, but is less likely to jump to a wrong conclusion. Both types of thinking are essential and you shouldn't think of one as being better than another. However, if you're not aware that your brain uses two different thinking styles then you can miss out on connections with people, be persuaded to make bad decisions or be less able to cope with mental health problems.