There are at least 175 different kinds of cognitive biases that can plague your research. Some of these biases have a context, for example, you come across some of these only during surveys. Nevertheless, it is useful to keep them in mind during any kind of research. Finding the right bias through the Wikipedia list is hard and therefore, Buster Benson came up with categories to group similar or complementary biases together. If we look at them by the problem they are trying to solve, it becomes a lot easier to understand why they exist, how they are useful, and the trade-offs (and resulting mental errors) that they introduce. The problems that biases help us address are information overload, lack of meaning, the need to act fast, and how to know what needs to be remembered for later. We have explained each with help from Benson’s work.
Too much information: There is too much information in the world and we filter out most of it. Our brain uses tricks to pick out information that is going to be useful in some way. However, the problem we face is that some of the information we filter out is actually useful and important.
We notice things that are already primed in memory, repeated often or stuff that has recently been loaded in memory. Biases that fall in this category - Availability heuristic, Attentional bias, Illusory truth effect, Mere exposure effect, Context effect, Cue-dependent forgetting, Mood-congruent memory bias, Frequency illusion, Baader-Meinhof Phenomenon, Empathy gap
We notice bizarre/funny/visually-striking/anthropomorphic things more than non-bizarre/unfunny things. Therefore, we tend to skip over information that we think is ordinary or expected. Biases that fall in this category - Bizarreness effect, Humor effect, Von Restorff effect, Negativity bias, Publication bias, Omission bias
We notice changes and we generally tend to weigh the significance of the new value by the direction the change happened (positive or negative) more than re-evaluating the new value as if it had been presented alone. Also applies to when we compare two similar things. Biases that fall in this category - Anchoring, Contrast effect, Focusing effect, Framing effect, Weber–Fechner law, Distinction bias
We notice information that confirms our own existing beliefs. Also, we tend to ignore details that contradict our own beliefs. Biases that fall in this category - Confirmation bias, Congruence bias, Post-purchase rationalization, Choice-supportive bias, Selective perception, Observer-expectancy effect, Experimenter’s bias, Observer effect, Expectation bias, Ostrich effect, Subjective validation, Continued influence effect, Semmelweis reflex, Bucket error, Law of narrative gravity
We notice flaws in others more easily than flaws in ourselves. Biases that fall in this category - Bias blind spot, Naïve cynicism, Naïve realism
Not enough meaning: We get only a small part of the information but we need to make some sense of it in order to survive. Therefore, we connect the dots and fill in the gaps with stuff we think we know (it might not be true).
We find stories and patterns even in sparse data. Based on whatever small information we have after filtering out, we never have the full story. Our brain reconstructs the entire picture to feel complete inside our heads. Biases that fall in this category - Confabulation, Clustering illusion, Insensitivity to sample size, Neglect of probability, Anecdotal fallacy, Illusion of validity, Masked man fallacy, Recency illusion, Gambler’s fallacy, Hot-hand fallacy, Illusory correlation, Pareidolia, Anthropomorphism
We fill in characteristics from stereotypes, generalities, and prior histories whenever there are new specific pieces or gaps in information. Conveniently, we then forget which parts were real and which were filled in. Biases that fall in this category - Group attribution error, Ultimate attribution error, Stereotyping, Essentialism, Functional fixedness, Moral credential effect, Just-world hypothesis, Argument from fallacy, Authority bias, Automation bias, Bandwagon effect, Placebo effect
We imagine things and people we are familiar with or fond of as better than things and people we aren’t. This has an effect on the perceived quality and value of the thing we are looking at. When conducting a survey, rather than looking at all the answers provided by the respondent, you place the individual in a certain group only because that individual has one quality or answers one question in a way that you “like”. Biases that fall in this category - Halo effect, In-group bias, Out-group homogeneity bias, Cross-race effect, Cheerleader effect, Well-traveled road effect, Not invented here, Reactive devaluation, Positivity effect
We simplify probabilities and numbers to make them easier to think about. Our subconscious does not do the math and generally gets things like the likelihood of something happening if any data is missing wrong. Biases that fall in this category - Mental accounting, Normalcy bias, Appeal to probability fallacy, Base rate fallacy, Murphy’s law, Hofstadter’s law, Subadditivity effect, Survivorship bias, Zero-sum bias, Denomination effect, Magic number 7+-2, Swimmer’s body illusion, Money illusion, Conservatism
We think we know what others are thinking. This means that we might assume that they know what we know, in other cases we might assume they are thinking about us as much as we are thinking about ourselves. We basically model their own mind after our own. Biases that fall in this category - Curse of knowledge, Illusion of transparency, Spotlight effect, Streetlight effect, Illusion of external agency, Illusion of asymmetric insight, Extrinsic incentive error
We project our current thinking and assumptions onto the past and the future. This is magnified by the fact that our subconscious is not good at imagining how quickly or slowly things will happen or change over time.
Biases that fall in this category - Hindsight bias, Outcome bias, Moral luck, Declinism, Telescoping effect, Rosy retrospection, Impact bias, Pessimism bias, Planning fallacy, Time-saving bias, Pro-innovation bias, Projection bias, Restraint bias, Self-consistency bias
Need to act fast: Without the ability to act fast in uncertainty, we would have perished long ago. However, while acting fast, we make decisions that are sometimes unfair, self-serving, or counter-productive.
In order to act, we need to be confident and feel what we do is important. In reality, most of this confidence can be classified as overconfidence, but without it, we might not act at all. Biases that fall in this category - Overconfidence effect, Egocentric bias, Optimism bias, Social desirability bias, Third-person effect, Forer effect, Barnum effect, Illusion of control, False consensus effect, Dunning-Kruger effect, Hard-easy effect, Illusory superiority, Lake Wobegone effect, Self-serving bias, Actor-observer bias, Fundamental attribution error, Defensive attribution hypothesis, Trait ascription bias, Effort justification, Risk compensation, Peltzman effect, Armchair fallacy
In order to stay focused, we favor the immediate, relatable thing in front of us over the delayed and distant. We value stuff more in the present than in the future and relate more to stories of individuals we know than anonymous individuals. Biases that fall in this category - Hyperbolic discounting, Appeal to novelty, Identifiable victim effect
We are motivated to complete things that we have already invested time and energy in. This helps us finish things, even if we come across more and more reasons to give up. Biases that fall in this category - Sunk cost fallacy, Irrational escalation, Escalation of commitment, Loss aversion, IKEA effect, Processing difficulty effect, Generation effect, Zero-risk bias, Disposition effect, Unit bias, Pseudocertainty effect, Endowment effect, Backfire effect
We are motivated to preserve our autonomy and status in a group, and we avoid irreversible decisions in order to avoid mistakes. If we must choose, we tend to choose the option that is perceived as the least risky or that preserves the status quo. For example, we tend to write on a topic in a way that appeals to the readers. This can be something about yourself or some phenomenon that everybody in the field accepts but may or may not be the truth. Biases that fall in this category - System justification, Reactance, Reverse psychology, Decoy effect, Social comparison bias, Status quo bias, Abilene paradox, Law of the instrument, Law of the hammer, Maslow’s hammer, Golden hammer, Chesterton’s fence, Hippo problem
We favor options that appear simple or that have more complete information over more complex, ambiguous options, even if the latter is ultimately a better use of time and energy. Biases that fall in this category - Ambiguity bias, Information bias, Belief bias, Rhyme as reason effect, Bike-shedding effect, Law of Triviality, Delmore effect, Conjunction fallacy, Occam’s razor, Less-is-better effect, Sapir-Whorf-Korzybski hypothesis
We can only afford to remember the bits that are most likely to prove useful in the future out of all the information out there. We need to make constant bets and trade-offs around what we try to remember and what we forget. However, some of the things we remember make the system more biased to the other biases.
We edit and reinforce some memories after we get a new piece of information. During that process, memories can become stronger, but various details can also get accidentally swapped. We sometimes accidentally add detail to the memory that is not there before. We may even reinforce it. Biases that fall in this category - Misattribution of memory, Source confusion, Cryptomnesia, False memory, Suggestibility, Spacing effect
We discard specifics to form generalities using implicit associations, stereotypes, and prejudices. Biases that fall in this category - Implicit associations, Implicit stereotypes, Stereotypical bias, Prejudice, Fading affect bias
It is difficult to reduce events and lists to generalities, so instead, we pick out a few items to represent the whole. Biases that fall in this category - Peak–end rule, Leveling and sharpening, Misinformation effect, Duration neglect, Serial recall effect, List-length effect, Modality effect, Memory inhibition, Part-list curing effect, Primacy effect, Recency effect, Serial position effect, Suffix effect
We store memories differently based on how they were experienced. Our brain only encodes information that it deems important at the time, but this decision can be affected by other circumstances like what else is happening simultaneously, how is the information presenting itself, can we easily find the information again if we need to, etc., ultimately changing the significance of the original memory. Biases that fall in this category - Picture superiority effect, Levels of processing effect, Testing effect, Absent-mindedness, Next-in-line effect, Tip of the tongue phenomenon, Google effect, Self-relevance effect