Mental Biases for When You Need To Act Fast


Our minds need to generate the best possible decisions for us and sometimes, they need to calculate the result much faster than usual.

This need to generate a quick decision makes our mind to take a defensive stance in favor of ourselves.

This results in false predictions and errors in judgment that skew our perspective of reality.

Mental Biases that Activate When We Need to Act Fast:

Mental Biases When We Need To Act Fast

Mental Bias: Overconfidence Effect

Overconfidence Effect is a mental bias where person’s subjective confidence in their judgements is reliably greater than the objective accuracy of those judgements, especially when self confidence is high.

If you think of an idea or something else that you would like to remember for later, you would most likely think that your memory is pretty good and that you can recall it. However, if you don’t write this idea you will most likely forget you even thought of it. There are people who think they can sing pretty well, without any real evidence but their self confidence, and they go to shows for singing only to be ridiculed by the reality that they can’t actually sing. Most people think they are stronger than others without any real evidence but their self confidence, and when they get into fights they face the reality that there are people much stronger than them.

Mental Bias: Social Desirability Bias

Social Desirability Bias is the tendency of survey respondents to answer questions in a manner that will be viewed favorably by others. It can take the form of over reporting good behavior or under reporting bad.

If you haven’t taken a shower for a couple of days because you were really busy, and someone speaks to you about how their coworker doesn’t shower and stinks, you would most likely lie about not showering yourself. You will blame your business but the reality is that you were simply lazy enough to not shower.

Mental Bias: Third Person Effect

Third Person Effect is the mental fallacy where people tend to perceive that a third party messages have a greater effect on others than on themselves.

If you hear someone telling you about a thing they heard on the news you would most likely think that this person is more influenced by mass media than you are. However, mass media influences all of us in different ways. For this person might have been the news, but for you it’s most likely wrong expectations from watching movies. However, we overestimate how unsusceptible we are.

Mental Bias: False Consensus Effect

False Consensus Effect is a mental bias where people tend to overestimate the extent to which their opinions, beliefs, preferences, values, and habits are normal and typical of those of others.

If you think that eating meat is normal and everyone who is normal should agree with this, vegan people are not normal for you. You think that your opinions, beliefs, preferences, values, and habits are normal and everyone who does not fit them is not normal, in this case vegans. But who can say if your opinions are normal when everyone thinks their opinions are normal. And if you look at majority of people to generate a norm than many of your own opinions, beliefs, preferences, values, and habits will not be normal.

Mental Bias: Hard Easy Effect

Hard Easy Effect is a tendency to overestimate the probability of one’s success at a task perceived as hard, and to underestimate the likelihood of one’s success at a task perceived as easy.

If you are a contestant on “Who Wants To Become A Millionaire?” You would most likely underestimate your ability to answer the easier questions. However, as the questions get harder you would most likely overestimate your ability to answer these questions correctly.

Mental Bias: Lake Wobegone Effect

Lake Wobegone Effect is a natural tendency to overestimate one’s capabilities and achievements especially in comparison with other people. We see ourselves as better than others.

If you start a new class right now with a new group of people your first mental perception of yourself in comparison to everyone in the class would be as superior. You would see yourself as a better person, as cooler, as stronger, as smarter. Until you befriend with someone, then you will accept them as individuals that are on your level. We tend to do this with strangers because we know ourselves, we know our journey and we have no idea about others’ journey. When we meet them we assume we have been through a lot more than they, so we assume ourselves as better. Just like in a movie, when we meet supporting characters we assume the main character as more important and better than these supporting characters.

Mental Bias: Dunning Kruger Effect


If you take a couple of classes of public speaking and you watch some expert give a public speech, you would think that your speech will be close to theirs in terms of quality and delivery. However, this will most likely not be the case. Your speech might be good, you might even give the best public speech you have ever given till then, but it will be far from the ones that the professionals give, the ones you watched. There are subtle things public speakers fight through and need to work on, things you are not aware of before you confront them. And mastering these things takes time and effort. But because you don’t know any of this before you start, you overestimate your ability of giving a speech.

Mental Bias: Egocentric Bias

Egocentric Bias is the tendency to rely too heavily on one’s own perspective or to have a higher opinion of oneself than what the reality actually is.

If you were asked whether you deserve a raise or not, you would most likely give a positive answer. Most people will say they deserve a raise, even if they are conscious of the fact that they might not put in the best work. However, if a mirror was put in front of you and you were asked the same thing, chances are you will be more fair and more real with your answer. Most people will answer fairly. When we are self aware we don’t or rarely succumb to this bias, but every other time we are mostly egocentric in our opinions and decisions.

Mental Bias: Optimism Bias

Optimism Bias is a cognitive bias that causes a person to believe that they are at a lesser risk of experiencing a negative event compared toothed people.

If you start smoking cigarettes you would assume that you are at a lesser risk of getting sick because you smoke. But this is not true. The chances of getting sick because of smoking are the same for you as anyone. Unless you have a clear evidence that your DNA is unaffected by smoking, that you are a different human than most, the chances are the same for you as for any other human.

Mental Bias: Forer Effect

Forer Effect is a psychological phenomenon whereby individuals give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically to them, that are in fact vague and general.

If you go to somebody who claims they can read your personality by looking at your aura you will be skeptical at first. But let’s say you go there and this person who reads auras says that you are a special person, that there is some inner battle within you, that you are anxious and shy but really courageous when you need to be, that you are really self critical and highly judgmental but you can defend yourself when needed, that you were hurt before really bad by someone, and everything you do now cannot really heal you of this emotional hurt, that you are really happy most of the time, but you are also sad and lonely deep inside. You will think that this person followed you your entire life. You will think they can really read your personality based on your aura. But the truth is that these descriptions, even though you think are really personal to you, they are really vague and general in reality.

Mental Bias: Self Serving Bias

Self Serving Bias is any perceptual process that is distorted by the need to maintain and enhance self esteem, or the tendency to perceive oneself in an overly favorable manner.

If you do a test in school and you score a good grade you will tell yourself it’s because you studied hard. However, if you score a bad grade you will tell yourself that it’s because the teacher doesn’t like you, or the test was unfair. Team plying any sport and winning the game will claim it’s because they trained really hard, but if they lose the game most often they blame the referees. Someone being hired will believe it’s because of their qualifications, but the same person not being hired will say that the interviewer didn’t like them very much from the start.

Mental Bias: Actor Observer Bias

Actor Observer Bias is a tendency to attribute one’s own actions to external causes while attributing other people’s behaviors to internal causes.

If you go to a doctor and they say you have a high cholesterol levels you will most likely blame this on genetics, or the environment, you might even blame your finances for not having enough to eat a proper healthy diet. However, if you find out someone else has high cholesterol levels you will most likely blame them for their poor diet and lack of exercise. So when it’s happening to us, it’s outside of our control, but when it’s happening to someone else, it’s all their fault.

Mental Bias: Illusion Of Control

Illusion Of Control is the tendency for people to overestimate their ability to control events. It occurs when someone feels a sense of control over outcomes that they demonstrably do not influence.

If you break up with someone you love you will most likely think it’s all or slightly your fault. You will think if you didn’t say something things would be different. But the truth is that the other person has a say in this too. Maybe the relationship was an issue for them for a reason that’s not you.

Mental Bias: Illusion Of Superiority


If you were asked to give a solution to a problem you had faced you will most likely assume your solutions are superior to those of others. But in reality these solutions worked solely for you, and there are expert in the field you are talking about that do countless researches on the topic.

Mental Bias: Fundamental Attribution Error

Fundamental Attribution Error is the concept that people tend to emphasize the character or intention, rather than external factors, in explaining other people’s behavior.

If you see someone who smells really bad because they didn’t shower, you would assume they are weird, that they are too lazy to have a proper hygiene or that something is wrong with them. But you don’t really know if this person didn’t have water at home, or if they fell into a sewer, or they might have even saved an animal that fell within a sewer. We tend to focus on other people’s character or bad intentions first rather than the external situations and uncontrollable factors. In an experiment subjects blamed that person’s behavior or personality 65% of the time.

Mental Bias: Defensive Attribution

Defensive Attribution is a cognitive approach that uses a set of beliefs and blame as a shield against the fear that one will be the victim or cause of a serious mishap.

If you hear that a group of teenagers was lost on a mountain on a bad weather you would most likely say something that kind of blames the teenagers. You will say what the hell were they doing alone, who in their right mind would climb a mountain on a bad weather, why were they on the mountain in the first place. You will blame the teenagers instead of the situation. And the lowest the level of similarity between the people involved and you, the bigger the chance you will blame them. But all of these reactions are a defensive mechanism to shield yourself from the fear that this might happen to you. You distance yourself from the victims involved because it gives you a sense of security. This protective mechanism gives you a sense that you have a bigger control over situations than you actually have.

Mental Bias: Trait Ascription Bias

Trait Ascription Bias is the tendency for people to view themselves as relatively variable in terms of personality, behavior and mood while viewing others as more predictable in their personal traits in different situations.

If you were asked to describe your best friend you will most likely portray them as a solid character who was and always will be the way it is, with the same group of traits and attributes they currently have. But if you were asked to describe yourself you will be much more fluid in your description. You will speak about traits you have, traits you are developing, traits you had but no longer have, traits you imagine to have. You will speak of yourself as couple of different characters and personalities in different situations. You will see yourself as someone who has a potential to change while others will be more solid in your depiction of them. This is because we see others in limited amount of situations and we create a solid definition about them. However, because we are with ourselves we know that we continuously change.

Mental Bias: Effort Justification

Effort Justification is a person’s tendency to attribute a value to an outcome, which they had to put effort into achieving, greater than the objective value of the outcome.

If you were given a set of humiliating missions you must accomplish to enter your favorite team, or to become a member of your favorite fraternity, and you accomplish them, you will attribute a greater value to the reward of getting in the fraternity. You will value your membership more by doing the humiliating missions than if you were just allowed to be a member without doing anything, even though it’s the same fraternity you favor.

Mental Bias: Risk Compensation

Risk Compensation is a mental bias suggesting people adjust their behavior in response to the perceived level of risk, becoming more careful where they sense greater risk and less careful if they feel protected.

If you were told to walk across a jungle that is known to have dangerous animals inside, you will be extremely careful. But if you were told to walk across the same jungle being told that a team of snipers is protecting you, or that the animals were removed, you will walk through it much carelessly.

Mental Bias: Peltzman Effect

Peltzman Effect is a mental fallacy where people react to safety regulations by increasing other risky behaviors and thus offsetting the safe behaviors the safety regulations are there to protect.

If you were given a pill that gives you consequence free recovery if you get really drunk, chances are you will be inclined more to get as much drunk as possible, even though you might not really want to without the pill.

Mental Bias: Hyperbolic Discounting

Hyperbolic Discounting is a tendency for people to increasingly choose a smaller and sooner reward over a larger and later reward as the delay occurs sooner rather than later in time.

If you were told that you will be given 100$ right now or you can choose to come here in a week and get 200$, most people will choose the 100$ right now. The bigger the delay of the reward the bigger the chance people will choose the momentary reward.

Mental Bias: Appeal To Novelty

Appeal To Novelty is a cognitive fallacy in which one prematurely claims that an idea or proposal is correct or superior, exclusively because it is new and modern.

If you get an update for your OS you would most likely assume that it’s better than the last one and you will update your device. But you have no idea in reality if it’s better or not. The update might have errors that damage your device, however, you assume it’s better because it’s the latest update, without any other evidence.

Mental Bias: Identifiable Victim Effect

Identifiable Victim Effect tendency of individuals to offer greater aid when a specific, identifiable person is observed under hardship, as compared to a large, vaguely defined group with the same need.

If you go on the internet you will see that the more known and famous countries of the world get bigger attention when a disaster strikes them, and smaller countries that go through same and maybe even more terrible disasters are not even heard of. Most people focus their attention, kindness and help toward the more famous countries just because they are more identifiable, while the need of help is the same, or maybe even greater in other smaller countries.

Mental Bias: Sunk Cost Fallacy

Sunk Cost Fallacy is a cognitive fallacy thinking you make rational decisions based on predictions and experiences while the decisions you make are derived by the emotional investments you accumulate.

If you invest small amount of money in some cryptocurrency and it starts rising, you will like to invest more. You invest more and you invest even more money as time goes by but the value of the cryptocurrency starts dropping. You would most likely keep the money in the stock, you will not take them out. And as it keeps dropping you will have a bigger resistance of getting them out. You might even double down. This is because the more you invest in something the harder it becomes to abandon it.

Mental Bias: Irrational Escalation

Irrational Escalation is a term frequently used in psychology, referring to a situation in which people can make irrational decisions based upon rational decisions in the past or to justify actions already taken.

If you’ve ever tried to climb a mountain, or attempted to reach some other physical or mental peak, and pushed yourself to go a bit further ‘because I’ve already come all this way’, you’ve escalated your commitment to a goal. Such escalation becomes irrational when the rewards from completing your goal would come nowhere near to covering the expenses you’ve paid to complete the goal. Sticking to a business plan that’s already costing more than it will give is a form of this bias.

Mental Bias: Escalation Of Commitment

Escalation Of Commitment is a bias where an individual or group facing increasingly negative outcomes from some decision, action, or investment nevertheless continues the same behavior rather than alter course.

If you start bidding and enter a bidding war with someone, this can be an example of this bias. You will both compete with your finances over something that in the end would turn out to be much less valuable than your commitment to win over your opponent.

Mental Bias: Generation Effect

Generation Effect is a phenomenon where information is better remembered if it is generated from one’s own mind rather than being read.

If you need to learn about a subject you would learn and remember less of it instead if it’s the same subject but it’s you who generates the analogies, metaphors, examples and ideas.

Mental Bias: Loss Aversion

Loss Aversion refers to people’s bias to prefer avoiding losses to acquiring equivalent gains, it’s the tendency to give more attention in avoiding a loss than gaining something equivalent.

If you are a regular person like everyone else, you don’t go out that much, but one night you go out with a new group of friends you just met, and for some reason you are in your best mode that night, you laugh, you are the life of the party, and the new friends love you, they praise you, they think you are the awesomest human being on the planet, you will feel great about yourself. Your ego will be boosted. However, you would avoid going out with the same group of friends because you would fear losing your status because you know you are not as awesome as you were that night. You would avoid losing your status instead of trying to have even better experiences.

Mental Bias: IKEA effect

IKEA effect is a cognitive bias in which consumers place a disproportionately high value on products they partially created or participated in their creation in some manner.

If you have two chairs, one you bought really expensively and looks really beautiful, and another customized by you where you were given 3 deigns to choose from, the texture and the size, maybe something personal to add, and you were given this chair to put together yourself, you will value the customized chair more than the really expensive one because you invested more energy and personal touch in creating it.

Mental Bias: Unit Bias

Unit Bias is the tendency for individuals to want to complete a unit of a given item or task. People want to finish whatever portion they have no matter the size, it is a perception of completion that is satisfying to people.

If you were served a small bowl of ice cream you would eat the whole bowl. However, if you were served a big bowl, twice the size of the small bowl, you would still eat the whole bowl of ice cream because you see each bowl as one unit, no matter if they are double in their size. This is because we have a tendency of finishing our portions, it gives us a sense of completion that is satisfying to us.

Mental Bias: Zero Risk Bias

Zero Risk Bias is a tendency to prefer the complete elimination of a risk even when there are alternative options that produce a greater reduction in risk.

If you were given two choices to gamble, the first one says you need to give 100$ and you have 1 in 5 chance to win 1000$ and the second option says you don’t need to give anything but you still have a chance to win 1000$ but with 1 in 50 chance, you would most likely choose the second option because you don’t put on any wager even though the chances of winning are 10 times worse than the first option.

Mental Bias: Disposition Effect

Disposition Effect is a mental bias that relates to the tendency of people to sell assets that have increased in value, while keeping assets that have dropped in value.

If you invested in a stock 1000$ and the value drops to 700$ you would most likely not sell and lose 300$ of your investment. But since the stock is losing value chances are that it will drop even more so you will lose more. In another case, if you invested 1000$ and the value of the stock grows to 1300$ you would most likely sell to gain 300$ profit, but the stock might grow even more and you lose potential profit. In the first case we tend to stick to assets that drop in value while in the second case we tend to sell assets that grow in value.

Mental Bias: Pseudocertainty Effect

Pseudocertainty Effect is a mental fallacy relating to the people’s tendency to perceive an outcome as certain while in fact it is uncertain. It is mostly observed in multi stage decisions.

If you list through 5 games of football and you see the teams competing, you will be certain at least for one game about who will win. You will claim that it’s how the game will end, maybe even claiming about what the exact score will be. But in reality this outcome is uncertain and you are under the influence of this mental fallacy.

Mental Bias: Processing Difficulty Effect

Processing Difficulty Effect is a cognitive phenomenon where people tend to remember more easily information that takes longer to read and is thought about more.

If you read about something explained in one paragraph and if you read about the same thing but explained in a couple of pages long, even if the explanation is longer but tells the same thing as the shorter and easier to read explanation, you will most likely remember more information via the longer and harder explanation than the shorter and easier one.

Mental Bias: Endowment Effect

Endowment Effect is the cognitive bias relating to the fact that people ascribe more value to things merely because they own them and not because of their actual worth.

If you have a dog and your friend has a dog, the same breed, the same age, let’s say even the same temperament, you will say that your dog is the best dog in the world, not because it won a competition, but merely because it’s yours.

Mental Bias: Backfire Effect

Backfire Effect is the tendency of people to resist accepting evidence that conflicts with their beliefs even if there are multiple sources giving out the same evidence.

If you believe that eating 5 eggs each morning is healthy, and you have done this your whole life, and someone presents you medical evidence that this is actually unhealthy, you would, most likely not accept the evidence. You will resist it. Even if multiple researches show up telling that the thing is unhealthy and there are no actual evidences that it was ever considered healthy, you would still resist accepting the evidence. This is because questioning your deeper beliefs that you acted upon most of your life takes a lot of energy for your mind, it needs to reorganize your whole belief structure, so it’s much easier and less energy consuming to ignore the evidence if it’s not an immediate threat to your life.

Mental Bias: System Justification

System Justification refers to the cognitive bias relating to the social psychological propensity of people to defend and bolster the status quo, that is, to see it as good, fair, legitimate, and desirable.

If you enter a society where it’s normal for women to do all the work while men need to take care of the home, and everyone around you does this and functions normally, works, laughs, goes out, if this is the norm of the society you are in instead of equality, you will adopt this behavior yourself. You will find reason in it, you will see what’s good within it, what’s fair and legitimate, what’s desirable and with time, you might even defend this norm. Some people might end up preaching it to others. It’s because whenever we enter a system we are wired to adopt the system’s rules and feel as part of that system, even if it means defending it.

Mental Bias: Reverse Psychology

Reverse Psychology is a cognitive fallacy where suggesting something opposite of what is desired when persuading someone will encourage the subject of the persuasion to do what actually is desired.

If you go out at your friend’s house and you find them cleaning the house you would by default wait for them to finish. But if they say to you that they need to clean and you shouldn’t bother helping them at all, you would most likely help them. We have aversion toward people knowing what we like to do, or what we intend to do. We don’t like to be manipulated and this makes us susceptible to manipulation.

Mental Bias: Reactance Bias

Reactance Bias is the tendency to do something different from what someone wants you to do in reaction to a perceived attempt to constrain your freedom of choice.

If you are a smoker but not really passionate smoker, but let’s say you were forbidden to smoke, a law passed in your country that smoking is not allowed, you and most people will most likely go out in protest and smoke even more than you did before. You will be more passionate about smoking just because the government forbid you, even though smoking is really bad for your health.

Mental Bias: Decoy Effect


If you were given two prices for two USB devices, the first one USB A has 15 GB of storage and costs 150$ and the second option USB B has 25GB of storage and costs 250$ you would get the one that fits your needs. But if there is a third option, a decoy option, let’s call it USB C with 20GB of storage that costs 300$ you would be pulled more towards the option B or the USB that costs 250$ and has 25GB of storage. Just because a decoy option is being put with a price that is higher in cost than the targeted price, but with lower worth in attributes than the targeted price, your mind will automatically assume that getting 25GB for 250$ is the best choice for you, even though you might just need 15GB USB device.

Mental Bias: Social Comparison Bias

Social Comparison Bias is having feelings of dislike and competitiveness with someone that is seen physically, or mentally, or status wise better than yourself.

If you are in a team with 3 other people and other people start praising one person of your team, they say this person is physically and mentally best in the team you are in, this means better than you, it would most likely trigger competitiveness within you, maybe even feelings of dislike for this person, just because they are described as better than you. The other two guys and you might get along really well, and you might avoid the so called superior teammate just because you are mutually inferior in other people’s opinion to this person n you team, even though they might be really good people.

Mental Bias: Status Quo Bias

Status Quo Bias is a preference for the current state of affairs where the current baseline is taken as a reference point, and any change from that baseline is perceived as a loss.

If you are a citizen in a city and the government tries to renovate the whole city, adding different look to the buildings, different infrastructure and adding new laws to the traffic to make the city you live in more in alignment with the cities from first world countries, you, and majority of the citizens would protest against the changes. You would assume it’s just for a profit, you would whine about how everything is in construction, about how the city was better when it wasn’t renovated, about every little detail against your preferences that you can find to highlight. This is because we don’t like change. We want to stick with things that are familiar with us. You would most likely drink the same beverage when you go out, you would most likely go to the same clubs in a city, you would eat the same couple of foods in a restaurant. People love to stick with what’s familiar, even if there are better options out there.

Mental Bias: Ambiguity Bias

Ambiguity Bias is a cognitive bias where people tend to select options for which the probability of a favorable outcome is known, over an option for which the probability of a favorable outcome is unknown.

If you are given a challenge to win 100$ if you guess correctly the color of a ball you would pick up from a box, and you are given two boxes with red and green balls to choose from, one box has 50 red and 50 green balls, and the other box has a random number of red and green balls, you would most likely choose to pick up balls from the box that has 50 red and 50 green ones. This is because people most often choose the option with known probability.

Mental Bias: Information Bias

Information Bias is the cognitive fallacy of believing that the more information that can be acquired to make a decision, the better, even if that extra information is irrelevant for the decision.

If you are given two choices, the first one is to learn the basics of public speaking and do it, and the second is to read a whole book on public speaking, than listen to powerpoint presentations from pros in public speaking, and then do it, you would most likely choose the second option even though the basics is all you need for your first public speech. Everything else than the basics you will learn from experience, yet you would like to absorb as much unnecessary info about the activity than just do it.

Mental Bias: Belief Bias


If you believe that all people who have green eyes are good people and you get a free coffee by someone who happens to have green eyes, you would assume it’s because he has green eyes therefore he must be a good person. But you have no idea about their intentions, you have no idea what they overcame to even be a good person if they really are. You fail to see there are bad people and good people with all eye colors.

Mental Bias: Rhyme As Reason Effect

Rhyme As Reason Effect is a cognitive bias whereupon a saying or aphorism is judged as more accurate or truthful when it is rewritten to rhyme.

If you are asked to tell what statement is more truthful between these “What sobriety conceals, alcohol reveals” or “What sobriety conceals, alcohol unmasks” you would most likely go with the first one just because it rhymes. However, “reveals” and “unmasks” are two different words with different aims. Reveals can be used about truths, lies, emotions, thoughts, about anything really, while Unmasks is more direct, it’s about diving deeper than the pretense and looking at the truth. Even if in this example the consequences of mixing the two words are not dire, because of this cognitive bias there can be serious unwanted implications in other cases.

Mental Bias: Law Of Triviality

Law Of Triviality is a mental fallacy that relates to the fact that people and organization give disproportionate weight to trivial issues leading them to complicate or even abandon the primary plan.

If you go out and you want to shop for a purse, and you want to buy a red purse, you will most likely find what you are looking for since you have a plan. Let’s say you go into one store and you find two red purses exactly like the one you wanted but they slightly differ in the shade of red. So you start thinking what of them is better, what shade of red is better. You think so much that you decide to come back after you decide. So you go home and think, you ask your friends, you search what’s the latest fashion, when suddenly you realize that the color is not important and you would get the darker red purse. So you go back to the store just to find that the purses were bought by someone. You obsessed with triviality and you forgot about what you really wanted.

Mental Bias: Delmore Effect

Delmore Effect is a mental fallacy where the simpler the problem to solve is, the more time we spend solving it while the more complex the problem is, the higher is the tendency to avoid the topic.

If you know what your purpose is and you know what your daily schedule is you would spend more time into organizing your daily schedule, you would stress more if something is not as you planned, something small, you would worry if you will achieve all the trivial things during your day like cleaning your mail, yet you would not spend even close to that time and energy into following your dream, your purpose, or creating your business you always wanted to create.

Mental Bias: Conjunction Fallacy

Conjunction Fallacy is a cognitive fallacy that occurs when it is assumed that specific conditions are more probable if told together than a single general one.

If you read about a woman named Linda who is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti nuclear demonstrations. And you are asked to choose what statement is more probable from these, “1. Linda is a bank teller.” or “2. Linda is a bank teller and is active in the feminist movement.” You would most likely choose 2. Because of her backstory. However, the probability of two events occurring together is always smaller than just one. Most people will ignore this fact and will attribute bigger probability based on, for example, description, as it’s in this case.

Mental Bias: Occam’s Razor

Occam’s Razor is a cognitive bias relating to the fact that the more assumptions you have to make for an explanation, the more unlikely an explanation is.

If you were asked what is more probable to be the truth in a case where two trees have fallen down during a windy night and there are two possible explanations, “1. The wind has blown them down.” or “2. Two meteorites have each taken one tree down and, after striking the trees, hit each other removing any trace of themselves.” You would most likely choose number 1 because there are less assumptions. Even though both are possible, several other unlikely things would also need to happen for the meteorites to have knocked the trees down. Most people decide how likely an explanation is based on the certainty and simplicity of the explanation.

Mental Bias: Less Is Better Effect

Less Is Better Effect is a type of preference reversal that occurs when the lesser or smaller alternative of a proposition is preferred when evaluated separately, but not evaluated together.

If you were asked for some reason to suggest how much you would pay for a particular set of dishes. The first set has 40 pieces with 9 broken pieces and the second set has 24 pieces all intact. If you are asked to bid a price about the first set first, than about the second set, you would most likely bid higher for the set with 24 intact pieces. But if you analyzed the sets together and bid for them together, you and all the people bidding would give the set with 40 pieces where 9 are broken, a higher price. When analyzed separately a greater majority of participants are willing to pay more for the second option, when analyzed side by side, the majority of the participants go for the first option recollecting that even if there are 9 broken pieces, there are still 31 pieces intact, versus 24 as there are in the second option.