French philosopher Descartes said, "Except our own thoughts, there is nothing absolutely in our power." But is that true?↵
In the past, it was believed that human beings indeed had power over how we thought. According to this view, anyone could be like Sherlock Holmes. You only had to think rationally, unaffected by biases and emotions. However, as we have discovered more and more about the brain and how it works, we have learned that this is not the case. The problem is that thinking is the work of the brain, and the human brain, as it turns out, does not like to be rational. In fact, it is structured in a way that it often prefers relying on a set of illogical thinking patterns instead of following reason all the time. The brain's illogical thinking patterns that make unsound judgments are called cognitive bias. There are many cognitive biases, but here are some of the most well known.

Kevin: I'm a strict vegetarian. I'm convinced that my decision not to eat meat is rational and based on objective research. It seems to me that there is abundant scientific evidence for the benefits of a vegetarian diet. Studies in favor of eating meat, on the other hand, seem few and unreliable.↵
Sara: I'm a strong advocate for a balanced meat and plant diet. I do not doubt that my belief is the most reasonable one, considering all the scientific evidence. It seems to me that the most reliable studies show that avoiding meat can be dangerous for one's health. The benefits of a vegetarian diet, on the other hand, are questionable at best.

Both Kevin and Sara are affected by confirmation bias. Confirmation bias is a type of cognitive bias that involves favoring information that confirms previously existing beliefs or biases. It impacts both how people gather information and how they interpret and recall it. Confirmation bias makes people unconsciously seek information that matches their own opinions, just as Kevin and Sara have done. When people encounter evidence that contradicts their view, confirmation bias helps them to interpret it in a way that supports their existing opinion or to dismiss it as unreliable. Thus, confirmation bias prevents us from looking at situations objectively, leading us to make poor or faulty choices.

Confirmation bias can appear in many forms. Racism, which is a dangerous human attribute that is essentially found in all societies, is an obvious example. So are prejudices against religion, gender, social class, and age. We even become firm in our loyalty to political parties and view them simply in "us" or "them" terms. Thus, we become hard wired to engage in faulty thinking.

It is almost impossible to overcome confirmation bias alone. However, Charles Darwin came up with a golden rule to avoid falling into the trap of confirmation bias. He always noted observations that were opposed to what he thought and made an effort to investigate them. Paying extra attention to claims that challenge your opinions and attempting to discredit your own beliefs allow you to come to a conclusion in a more objective way.

Are you going to watch that movie that is currently number one at the box office, even though you usually dislike superhero movies? Is that popular brand of crispy chips also your new favorite snack, even though you usually hate oily snacks? Do you love the new hairstyle that most teenagers are wearing now, even though you thought it looked silly before? If so, think again! You may be under the influence of the bandwagon effect.

In psychology, the bandwagon effect refers to a phenomenon in which people do something primarily because other people are doing it, regardless of their own beliefs. Since human beings are social animals, the desire to conform is a part of our nature. Nevertheless, the bandwagon effect may have negative effects. It may cause people to vote for an already popular political candidate without carefully examining his or her character and policies. Worse, voters may be tricked into believing a certain candidate is popular and into supporting him or her.

This is how Adolf Hitler came to power early in his political career. When the Nazi party was new and unknown, he used radio broadcasts to make his party appear important and popular, and this convinced many German people to vote for the Nazis without knowing much about what the party really stood for. When Hitler and the Nazi party became popular, it was even easier to gain more and more supporters. People wanted to support the popular party because their friends supported the party, in spite of its horrible beliefs and actions.

Doing what most people do is not always wrong. Sometimes products and ideas are popular because they are indeed good, and unpopular ones are avoided for good reasons. However, this is not always the case. That is why it is advisable to be aware of the bandwagon effect and guard yourself against it, even if you eventually decide that "most people are right. As Mark Twain said, "Whenever you find yourself on the side of the majority, it is time to pause and reflect."The German people unconditionally advocated the Nazis. This is a typical example of the bandwagon effect.

Framing is presenting an issue, argument, or statement in a certain way so that it will influence the audience's feelings or opinions. When such manipulation succeeds in altering the audience's decisions or judgments, it is called the framing effect.↵
We encounter framing effects everywhere in our daily lives. One of the areas where it is particularly useful and constantly used is business. For example, a customer may decide not to buy a gym membership that costs 500,000 won a year because it sounds too expensive. However, if the same membership is advertised as only 1,370 won a day, that same consumer may consider it cheap and eagerly purchase it.

The framing effect is also common in the mass media, where it often has a decisive impact on public opinion. Consider the fact that EU migrants cost the UK government ₤408.12 per second in public expenditures and contribute ₤463.35 per second in revenue. A newspaper may have a headline saying "EU migrants cost the UK government ₤408.12 per second in public expenditures" and add the rest later in the article, which will immediately lead many readers to have a hostile attitude toward immigrants. Another newspaper may write "EU migrants contribute ₤463.35 per second in revenue" as a headline and put the rest later, which will generate a completely different response among its readers.

There are several ways to prevent yourself from being influenced by the framing effect. First, you can reframe the information in your own way. For example, you can calculate how much a gym membership would cost per month or per year even though the gym owner advertises it as 1,370 won a day. Another way is to consider options and possibilities that are not included in the information. Some questions are framed in such a way that you are shown only two choices: Is competition good or bad? When you are faced with a question like this, it is important to remember that the effects of competition may differ according to the context.

These are only a few examples of many cognitive biases. Unfortunately, most of us are influenced by cognitive biases. What makes them dangerous is that they prevent us from realizing how unreasonable and unfair ideas may be. Therefore, accepting that we are not always right or logical is the first step to fight cognitive biases. Once we admit that our opinions may be biased, it becomes easier to accept the information that we do not like. Only then will we truly have the power over our thoughts that Descartes believed we had.

Imagine you are in traffic and you have to make a left turn. While you are turning, you try to multiply 17 by 24 in your head. You'll either quickly abandon the math problem or you'll wreck your car. But what if you only had to add two and two while making the turn? You could do it easily. What is the difference between the two tasks? Most people would say that one of the tasks is easy and the other is hard. But Daniel Kahneman, who won the 2002 Nobel Prize in Economics, says that there is more to it.

Kahneman says we solve almost all problems with two very different types of thinking: System 1 thinking and System 2 thinking. Adding two and two is done using System 1 — fast thinking that comes to mind automatically. The product of 17 and 24, however, uses System 2 — slow, deliberate thinking that you have to practice.

System 1 is fast, intuitive, and emotional; it operates automatically. It is most helpful in familiar situations when time is short and immediate action is required. On the other hand, System 2 is slower; it requires more thinking. You have to plan ahead and consider all your options.

Most of the time, we are experts at what we are doing. We believe our impressions and act on our desires, so we use System 1 to solve most problems. System 2 watches what we do in the background and allows System 1 to control the situation. System 2 takes over when System 1 runs into difficulty. Another task of System 2 is to overcome the impulses and habitual patterns of System 1 when System 1 makes us feel overconfident about what we know and fails to acknowledge our ignorance, which leads us to make mistakes. System 2 is in charge of second-guessing and controlling our impulses. It helps us think twice about our decisions to make sure they are reasonable.

According to Kahneman, System 2 clearly produces the superior answers in most situations. As a way to live our lives, however, constant control by System 2 is not necessarily good, and it is certainly impractical. The best we can do is to learn to recognize situations in which mistakes are likely and try to avoid these mistakes when what we are doing is really important.