types of cognitive bias — 1 investigation

i looked into the various types of cognitive bias, originally, because mike at the bar accused me of having at least four of them in active rotation. i counted seven, conservatively. mike then suggested the counting itself was probably a bias of some kind. mike is now eight beers in and may, somehow, have a point worth writing down.

so this is the count, written from the desk, while carla is upstairs in some session about something with slides. i have, give or take a coffee refill, until the meeting on the third floor breaks for water. that is the runway. the runway is enough. the list is shorter than mike’s tab and longer than i’d like.

if you came here for the household one with the diagrams, the longer piece on confirmation bias is sitting in a different drawer of this site. the rest of you, stay. i’ll be moving fast. 23% on the phone battery. that’s also a bias, but not the kind they teach.

1. types of cognitive bias, the brief that fits on a napkin

here is the brief, which mike, in fairness, could have told you in fewer words. the brain runs about a dozen shortcuts at any given hour, and we call them biases when they go wrong and intuition when they go right. they are the same shortcuts. you do not get to know in advance which one is on shift. that is the whole shape of the problem and the whole reason this list exists.

the textbooks list close to two hundred of these. some are real. some are arguably the same one wearing a different jacket. the ones that show up in an actual tuesday, by my honest count, are seven. i’ll take them in the order they ruined my week. the order is not alphabetical. the order is autobiographical, which is, if you’re keeping score, already a bias.

and yes, every meeting could be a 3-line email. mike said this too, between his fifth and sixth beer, and i am stamping it here because if you object to it, you are objecting on confirmation bias, which is item two, which is convenient.

2. confirmation, the bar one

confirmation bias is the bias of looking for evidence you’re right and treating the rest as background noise. it is, of all the types of cognitive bias, the household leader. mike accused me of it on a wednesday. i defended myself by listing three times i had been correct that month. mike pointed out, calmly, that this was the bias defending itself with the bias.

here is how it shows up around me. i decided last week the third yoga mat under my couch was “still useful”. my evidence was that it had not, technically, decomposed. the evidence i ignored was every other tuesday since 2023. the brain treated the non-decomposition as a fan in the stands and the non-use as a heckler. the heckler was ejected. the mat sits, judging me, alongside the air fryer.

the trick within the trick is that knowing the definition does not, in any practical sense, protect you from the thing. i know about confirmation bias. i am, right now, writing about confirmation bias. i will, in approximately ninety minutes, fall victim to it about whether the cheese in my fridge is still edible. the cheese does not care about my book learning. the cheese is, in this metaphor, reality.

3. anchoring, the cerveza-price one

anchoring bias is when the first number you hear, however unrelated to anything, becomes the gravitational center of every number after it. you are not aware you are anchored. you cannot become unanchored by being told you are anchored. that is the whole engineering of the anchor.

i’ll give you mine, from the corner bar. the first beer at the corner, in 2019, cost a number i will not write down because writing it down would anchor you. since that first beer, every other beer i have ever paid for, anywhere, has been compared automatically against that one. when a barman in a different city tells me a price, my brain does not hear the price. it hears the delta against 2019. that is anchoring. that is the cerveza-price one. i am, on this front, lost. mike has not filed since 2019, which is not unrelated. mike’s anchor is the year his accountant moved away and every april since has been measured, in his head, against that one. mike is also lost. we are, on different vehicles, on the same lost road.

the worst version of anchoring is when the anchor is yours and you don’t know it. the rent number i pay is anchored to the cheaper one i used to pay. every rent number i hear from anyone is now a delta. their rent is not a number. their rent is, to me, a subtraction. the subtraction is the bias. the subtraction is, by my count, running right now.

4. availability, the microwave one again

availability bias is when the brain treats “things i can easily remember” as if it were the same set as “things that actually happen”. they are not the same set. memory is a small, vivid sample. the world is a large, dull sample. the brain prefers the small vivid one because the small vivid one fits in the cup.

here is mine, said plainly. i have killed seven microwaves. when somebody mentions microwaves, my brain does not produce “a useful kitchen appliance most people use without incident”. it produces, in vivid color, the flash from the third one and the smell from the fifth and dave laughing for nine straight minutes on the phone after the seventh. (i timed the laugh. of course i timed it.) on the strength of seven personal incidents, my brain has concluded microwaves are statistically dangerous appliances. they are not. i am the danger. the appliance is innocent. the sample is rigged.

this is, incidentally, the same shape as your news feed. it is not the world that is on fire. it is the sample. the feed is the small vivid cup. you are reading it like the bowl. showers over 4 minutes are theatre, by the way, and i bring it up only because i thought of it in one of those small vivid moments and the brain wanted me to write it down before the next bias took the floor.

5. hindsight, the dad-quote one

hindsight bias is the conviction, after a thing has happened, that you saw it coming all along. you did not see it coming. you can prove this by checking your text messages from a week before. nobody, including you, sees anything coming. the brain, after the fact, edits the tape so the foreshadowing is louder than it was on first viewing.

my dad used to say, on the topic of any decision i had just made and was already regretting, “i could’ve told you that.” and the thing about that line, which i did not understand for years, is that he could not have told me that. he was experiencing, in real time, hindsight bias. so was i, on the receiving end, by agreeing with him. we were two people in the kitchen, looking at a broken thing, both convinced we had foreseen the breaking. we had not foreseen the breaking. we had, in fact, foreseen, on the thursday before, the opposite of the breaking. but the broken thing was, at that moment, the only data on the table, and the brain rewrote everything backward to match.

this is the bias that haunts every retrospective meeting. the team gathers. the team looks at the result. the team agrees, with calm faces, on what should have been obvious from the start. the team did not, in fact, find it obvious from the start. the team’s slack from the start is, in many cases, still searchable. nobody searches it. searching it would cost the meeting its tone.

6. the chatgpt bias, the new one

this one is not in the manuals because the manuals haven’t caught up. chatgpt, in my apartment, is the new household bias, and it works like this. i ask chatgpt a thing. chatgpt gives me a confident, well-formatted answer. the formatting itself becomes evidence, in my head, that the answer is correct. the bullet points are doing some of the work. the calm voice is doing some of the work. the fact that there is no visible doubt is doing most of the work. it is, structurally, the same trick as a man at the bar with a beard who seems sure.

i am not above this. i ran a question through it last week about a thing i already half-knew. it gave me back, in three paragraphs, my own half-knowledge sharpened into a confident summary. i felt, briefly, like an expert. i was, in fact, looking at my own opinion in a clean shirt. that is the chatgpt bias. it is anchoring meets confirmation meets availability, dressed for a meeting it does not have to attend.

the simpsons, muted on the bar tv, made this point in 1992, give or take, with homer reading a self-help book and concluding the book agreed with him about everything he was already doing. the show has been, on this front, ahead of the manual for three decades. the manual is catching up. the manual will, predictably, take credit.

7. verdict, the list is the bias

and one more thing, before the runway runs out. if you came here on the way to a sideways post about being a tourist abroad, the same machinery is at work over there. an idiot in another country is just an idiot with anchoring on the wrong currency, availability on the wrong landmarks, and hindsight on the wrong tuesday. the rooms change. the wallpaper does not.

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