Cognitive Biases and How They Lead to Bad Decisions

Source: Pexels/MoosePhotos

A cognitive bias is a mental shortcut or heuristic intended to spare us time, effort, or discomfort—often while reinforcing our self-image or worldview—but at the cost of accuracy and reliability.

For example, in explaining the behaviour of others, we tend to overestimate the role of character traits over situational factors—a bias, called fundamental attribution error (FAE), which goes into reverse when it comes to explaining our own behaviour. Thus, if George fails to mow the lawn, I indict him with forgetfulness, laziness, or spite; but if I fail to mow the lawn, I am likely to absolve myself on the grounds of busyness, tiredness, or inclement weather.

Well over a hundred cognitive biases have been identified. After studying them, I found that most fitted into one of just eight groups, clusters, or themes:

1. Errors of salience
2. Errors of attention
3. Errors of association
4. Errors of framing
5. Errors of attachment
6. Errors of conformity
7. Errors of control
8. Errors of infallibility

In this post, the first in a series on cognitive biases, I’m going to look at the first group: what I have called errors of salience.

Remember that there can be a lot of overlap between named biases. Instead of trying to distinguish them, focus instead on the principles at play.

Errors of salience: Salience effect, availability bias, and neglect of probability

We tend to focus on whatever stands out most, losing sight of the bigger picture (salience effect). A plane crash that kills a few dozen people makes the headlines, but depression, which affects up to one in five of all people and leads to countless suicides, never makes it onto the front page (availability bias). As a result, people are more likely to worry about flying than to worry about depression (neglect of probability). If a meeting has an agenda, people will discuss the points on the agenda rather than any more pertinent matters. In this sense, the agenda sets itself, simply by having been thrust into everyone’s face.

In On the Nature of the Gods (45 BCE), Cicero relates how a friend of the atheist Diagoras of Melos (fifth century BCE) tried to persuade Diagoras of the existence of the gods by pointing to the great number of votive pictures of people being saved from storms at sea—to which Diagoras replied, “There are nowhere any pictures of the many who have been drowned.” One day, Diagoras found himself in a storm at sea, and the ship’s crew thought that they had angered the gods by taking an atheist on board—leading Diagoras to wonder whether all the other ships caught in the same storm also had a Diagoras on board.

During the Second World War, the statistician Abraham Wald examined the damage on returning bomber aircraft, and recommended reinforcing those areas that showed the least damage—since the planes hit in those areas were the ones that never returned.

Errors of salience: Publication bias and feature-positive effect

If a scientific study appears to show some effect, it is more likely to be published, even though it is an outlier (publication bias). In contrast, the falsification of a hypothesis struggles to get noticed and, certainly, never attracts a Nobel Prize. Studies that show that antidepressants work are more much likely to get published than studies that don’t, creating the impression that antidepressants are a lot more effective than they really are.

Absence, for example, of pain or pollution, is harder to notice or care about than presence (feature-positive effect). Tell me, what has been the greatest medical achievement of recent decades? Probably, you did not think to reply, "Discouraging people from smoking."

Errors of salience: survivorship bias and alternative paths

Successes, for being successful, are much more visible or prominent than failures. But for every successful singer or startup, there are thousands of invisible ones who never made it—leading us to overestimate our own chances of succeeding (survivorship bias).

Also, when looking at successes, all we see is the success, and not the sacrifice. A banker with a net worth of $10 million may no longer have the health or quality of soul to enjoy his money. Much better to have made just $2 million, acquired less recklessly (alternative paths). Money is not just money, but comes at the cost of invisibles such as health, relationships, and opportunities. What’s more, the person who made just $2 million may have contributed more to society, which is a different, more valuable but less visible, kind of reward.

Bias Essential Reads

What Accounts for Anti-Immigrant Prejudice?

Would You Wear Hitler's Sweater?

Now read the second post on this series, on errors of attention.

Neel Burton is author of Hypersanity: Thinking Beyond Thinking.