cognitive biases list — 1 explainer, sort of

a complete list of cognitive biases, ranked by how often i quietly deploy them in a given week, would, an explainer of sorts has informed me, take longer to write than the week itself contains hours. i started the list anyway, in pencil, on the back of an envelope. i made it to bias number nine.

desk again. carla is upstairs at the q3 review and the floor is, for once, polite. i have, give or take a hallway, fifty quiet minutes before the first email pretends to be urgent.

the envelope, in my defense, was the one the supermarket flyer came in, and i was already standing in the slow lane behind a man with twelve coupons and the patience of a saint. the printed list i was copying — pinned to the corkboard near the entrance, three columns, small font — looked authoritative. i memorized it. i wrote it down later. by the time the cashier rang me up i had a cognitive biases list of nine items, three opinions, and one strong feeling that the corkboard had been put there by a man with a master’s degree and a grudge.

cognitive biases list: a roster of the small repeatable mistakes the brain makes when it would rather feel right than be right. anchoring, availability, halo, recency, sunk cost, planning fallacy, in-group, optimism, confirmation. nine names. each one is a different angle on the same trick — the brain protecting the feeling, while the evidence sits on the counter.

A. LIST. IS. NOT. AN. EXCUSE.

some people will read a list of biases and treat it as a permission slip. i recognize the symptom. i decided, on tuesday morning between the cereal aisle and the eggs, that the only honest use of a cognitive biases list is the one where you cross items off as you catch yourself doing them. by friday i had crossed off all nine and added two i had invented. that is the mechanism. that is the post.

the better long-form on the underlying mechanism — the brain treating its own beliefs as the home team — sits at the cluster pillar on confirmation bias, which is the door you walk through before you start naming the rooms. this list is a map of the rooms. that pillar, frankly, is the building.

cognitive biases list, brief, with the corkboard typography preserved

so the cognitive biases list, as i copied it, in the order it was printed, with the small comments i added later in a different pen because the first pen had run out by item four:

1. anchoring — the first number you hear becomes gravity. any other number is judged against it, even when the first number was a typo.
2. availability — what you remember most easily becomes what you believe is most common. last night’s news beats last decade’s data, every time.
3. halo effect — one nice trait blurs the others into a soft glow. tall people get to be wrong longer.
4. recency bias — the last thing that happened to you is, in your brain’s filing system, the entire pattern.
5. sunk cost — money already spent should not influence the next decision; it always does. the third yoga mat is, technically, here.
6. planning fallacy — every project will take longer than you think, including this one.
7. in-group bias — your team’s mistakes are context. their team’s mistakes are character.
8. optimism bias — the bad thing happens to other people, statistically, until it arrives at your apartment in a beige envelope.
9. confirmation bias — the warm bath of agreeing with yourself, covered, in painful detail, in the pillar above.

that’s nine. the corkboard had eleven. the last two i couldn’t read because someone had stapled a pizza menu over them. i’ll allege they exist and move on.

mike’s bar list, transposed, mostly correct

i brought the envelope into the office. the imitation game was paused on a screen at the back of the breakroom — somebody had it open at the cipher scene, and nobody had un-paused it. mike, of all people, was in the lobby downstairs. he had come, he said, to pick up his nephew’s resume from a guy on the second floor and the guy had left for lunch. mike was holding a coffee from the cart on the corner and looking at the wall directory like it had personally insulted him. mike does not visit offices. mike treats offices the way most people treat dental work — necessary, briefly, never spoken of after.

i showed him the envelope. mike read the cognitive biases list with the flat expression he reserves for instruction manuals. then he handed it back and said, “you’re missing the one where a man at a bar tells you a thing and you believe him because it’s tuesday.”

i told him that was three biases stacked. mike said, “fine. i’m a stack.” mike has a system for taxes; he has not filed since 2019. it occurs to me, occasionally, that mike’s confidence in his own framework is itself a bias, but i am not the man to point it out, especially in a lobby with cameras.

he reordered my list, by the way, in the elevator, on the way back down. he said anchoring was first because everything else is downstream of it. he said sunk cost should be last because by the time you notice it the money is already gone and the list is just paperwork. mike’s edit was, annoyingly, better than mine. i kept it.

tom’s volvo list, allegedly produced over a weekend

tom — university tom, two-kids tom, owns-the-driveway tom — texted me a list of his own. tom does not call it a cognitive biases list. tom calls it “things to watch for in q4 planning”. tom’s list is the same nine items in a different costume. anchoring is “be careful with the first vendor quote”. availability is “don’t budget by what you remember from last quarter”. halo is “don’t promote on charisma”. sunk cost is “kill the project that isn’t working”.

tom’s version reads cleaner because tom has a volvo and a pension and a meeting calendar that goes seven weeks deep. mine reads grumpier because i have a yoga mat under the couch and an envelope. we are looking at the same nine rooms. tom is renting a backhoe. i am pacing the carpet. we are both, technically, surveying.

i don’t begrudge tom this. tom is the man your cognitive biases list survives contact with. mine survives, mostly, in the form of a worse mood.

productivity bro’s tweeted list, which is twenty-seven items long

the algorithm served me, that same evening, a thread by productivity bro. twenty-seven biases. each with an emoji. each with a “✅ how to fix it” sub-bullet. fix anchoring by “setting your own anchors first” — the bro version of anchoring is a productivity move. fix availability by “curating your information diet” — i am, a person who has ten coupons in a wallet that is not a wallet, the wrong audience for this advice.

productivity bro’s list ended with the line “screenshot this for the next time your brain tries to lie to you”. i did not screenshot it. i had, instead, the envelope. the envelope outperformed the thread for one practical reason — i had to write it by hand, slowly, in pencil, in the slow lane, while the man with twelve coupons argued about a price that had been clearly marked. writing by hand is, i think, a small bias-correction in itself. the brain has to slow down enough to choose each word. some of those words come back as truer than the ones the thumbs would have picked.

productivity bro’s other crime is making the cognitive biases list sound like a productivity hack. it is not. it is a description of the weather. you don’t fix weather. you wear a coat. and even then, sometimes — see also the longer post on how to be smarter, which is mostly about owning a coat — you forget the coat. that’s a category we will get to.

my list, the only honest one, signed in pencil

the only honest cognitive biases list is the one where you, the reader, write your own next to mine and find that yours is shorter, dirtier, and more accurate. i will list mine. you list yours. the lists do not have to agree. they have to be, both of them, written.

• the slow-lane bias — i overestimate how informed i am because i read things while waiting in lines.
• the corkboard bias — anything pinned in a public place becomes, in my head, peer-reviewed.
• the second pen bias — when a pen runs out and i pick up a different one, the second half of any list i write is more confident, because the new pen feels expensive.
• the seventh microwave bias — i still believe, against six prior data points, that this microwave is the one that survives.
• the saturday bias — i think i am smarter on weekends, possibly because i’m not at the desk.
• the 2 am revelation bias — anything thought at 2 am, written in a notebook, looks profound until 8:42am the next morning, at which point it reads like ad copy.
• the volvo bias — i assume tom is a better person because he drives a volvo. he might be. but the volvo is, i suspect, doing some of the work.

seven items. mine. yours might be different. if any of them are, in fact, the same as productivity bro’s twenty-seven, that’s also a finding. it means the bro and i, under different costumes, are in the same room, with the same wall, looking at the same three pieces of spaghetti.

verdict, the list is itself a bias

the cognitive biases list i copied off a corkboard while a man counted twelve coupons is, on its own terms, a bias. the act of writing nine items down implies the existence of nine items. there are, almost certainly, more. there are, almost certainly, fewer that matter. picking nine is a planning fallacy about the count of biases. i know what i did. i am noting it plainly of this very post.

the only practical use of a list like this — and the cluster moron-adjacent neighbor at the longer take on the word moron covers the failure mode in the language register i save for the bar — is to keep it nearby and uncrumple it occasionally. i don’t reread mine. i hand it to other people, like a moron with a flyer, and watch them recognize themselves in items three and seven. then i take the envelope back and put it on the shelf with the other unfinished homework.

that’s the use. that’s the upper bound. anyone selling more is selling productivity bro’s screenshots.

the envelope is on the desk, half-flattened, item nine still readable. carla is on her way back; the q3 review broke up early, by the sound of the elevator. i’m putting the envelope in the second drawer for tonight, where the third yoga mat memo and a year-old gym renewal also live, undisturbed.