The 5 most dangerous biases that sabotage your decisions

26/03/2026

Cognitive biases are ever-present in our thinking. Some are fairly easy to spot, while others are extremely difficult to notice. It's hard to rank biases by how dangerous they are, because each one can be dangerous in its own way. I have listed here five biases that may be slightly more dangerous than others, as they are directly related to how we perceive our own role in our interactions with other people and with the world.

1. The Bias Blind Spot

This is perhaps the most insidious bias: it is the tendency to recognise cognitive biases in others' thinking, but the observer fails to notice the biases in themselves.

Why it's dangerous: When we believe we are objective and others are "biased," we are unable to be self-critical. It prevents us from learning from our mistakes and makes constructive dialogue impossible, because we assume others are either stupid or evil when they disagree with us.

Example: You read a list of cognitive biases and immediately think about how well they describe your neighbor or political opponent, but you don't realize they influenced your own decision yesterday.

Here's how to tackle this: Always remember that you have the same biases as everyone else, and you're not immune to them. It's not worth looking for the same mistakes and flaws in others that you have in yourself. To spot your blind spots, ask a friend for help and an outside perspective.

2. Normalcy Bias

This is the tendency to underestimate the likelihood of disasters and their consequences. Our brains assume that because things have gone more or less the same way up to this point, they will continue to do so.

Why it's dangerous: It causes people to freeze in crisis situations. It's why people stay in their homes as a hurricane approaches or fail to react to a market bubble bursting or the early signs of a pandemic. It leaves us unprepared for exceptional circumstances.

Example: In the event of a fire, people may continue eating in a restaurant or calmly pack their belongings because their brains refuse to believe that their normal routine has just been interrupted by a life-threatening situation.

Here's how to tackle this: Being prepared for various situations, such as crises, makes it easier to take action. Remember that the world is a big and unpredictable place; many things can happen, and a surprise could be just around the corner. Even if a scenario is unlikely, that doesn't mean it can't happen. It's worth observing your familiar surroundings from time to time with a critical eye to identify any potential hidden dangers that could be eliminated.

3. Scope Neglect

We have difficulty grasping large numbers emotionally. We are more likely to help a single suffering child whose story we know than a million people suffering from famine, whose plight is presented as a statistic.

Why it's dangerous: It leads to irrational resource allocation and policy. We may spend millions of euros to solve a single small and visible problem while leaving massive, life-saving efforts unfunded because their scale is "too large" to be understood emotionally.

Example: People are often willing to donate more money to save a single oil-covered bird than to save 20,000 birds, because the mind "visualises" a single bird, but 20,000 is just an abstract number.

Here's how to tackle this: Humans have not evolved to comprehend large numbers or large scales; these expectations have emerged as society has developed. Intrinsically linked to this bias is framing bias and benchmarking—that is, points of reference that help us grasp numbers and scales. Don't try to increase the scale; rather, reduce it so you can grasp the issue more easily.

4. Naïve Realism

This is the firm belief that we see the world exactly as it really is, without any filters. We assume that any rational person would reach the same conclusions if they had access to the same information.

Why it's dangerous: It is a source of polarisation and conflict. When someone disagrees with us, naive realism leads us to conclude that the other person is either misinformed, stupid, or intentionally malicious. It prevents us from understanding that everyone interprets the world through their own historical and cultural lenses.

Example: Disputes over politics or history quickly turn hostile because both sides believe they hold the "objective truth" and view the other side as deluded.

Here's how to tackle this: Recognising that everyone has their own unique way of seeing the world. Keep in mind that we also have misconceptions about things; let's not deny this, as it makes us arrogant. Let's be open to other perspectives and be ready to learn and update our knowledge when necessary, especially if we realise we're wrong.

5. The False Consensus Effect

We constantly overestimate how many others share our opinions, beliefs, and values. We assume we are "more normal" and more representative than we actually are.

Why it's dangerous: It creates a false sense of security and blinds us to alternatives. In the business world, it leads to products that nobody wants, and in politics, to surprises at the ballot box. It makes us believe that "everyone knows this," even though in reality our view may be very marginal.

Example: An X user believes the entire nation shares a certain opinion because the circle they follow agrees, and is shocked when the election results turn out to be the opposite.

Here's how to tackle this: Remember: We are all unique individuals with a unique world-view and perspective on the world. We naturally seek confirmation (confirmation bias) for our own views so that we feel we are part of a larger group and safe.

Remember: The ultimate purpose of all biases is to protect us and conserve energy for our own protection and survival. It's worth remembering that humans naturally resist change, and we don't readily admit when we're wrong. We often forget that we are unique individuals with unique characteristics, including our thoughts and views.

Sometimes our thinking is simply aimed at protecting us and pays little heed to the truth. Truth is, in any case, a subjective and elusive concept, so it is important to be open-minded when discussing things with others. The human brain has not evolved to comprehend everything, because humans are relatively small creatures, and we view things from our own scale, which is tied to the size of our own bodies.

Summary

In summary, I would say: Our own subjectivity is the root of all biases, and it cannot be eliminated or changed. Our unique personality and mind are our greatest strengths, as long as we remember that other people are built in the same way.