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Formal versus Ecological Rationality
Philosophy professors who present students with contrived thought experiments, like whether it is permissible to throw a fat man over a bridge to stop a runaway trolley which threatens five workers on the track, often get frustrated when students look for loopholes, like shouting at the workers to get out of the way. Yet that is exactly the rational thing one would do in real life.
Classical versus Family Resemblance Categories
A third reason that rationality will never be reduced to logic
Logical Computation versus Pattern Association
“hidden” layer of neurons between the input and the output, as shown on the next page. This changes the network from a stimulus-response
creature to one with internal representations—concepts,
The networks are called deep learning systems because of the number of layers between the input and the output
Human rationality is a hybrid system.
time and chance happen to them all. An essential part of rationality is dealing with randomness in our lives and uncertainty in our knowledge.
“random” in common parlance refers to two concepts: a lack of patterning in data, and a lack of predictability in a process.
Brevity is the soul of pattern: we say that a dataset is nonrandom when its shortest possible description is shorter than the dataset itself.
This credence estimate is sometimes called the Bayesian interpretation of probability
frequentist
availability heuristic.
data came to be considered a public good.
it. We
implemented billions of dollars of dubious safety measures, like installing bulletproof
communal outrage
victim narrative: a moralized allegory in which a harmful act is sanctified, the damage consecrated
The goal of the narrative is not accuracy but solidarity.
People avidly consume data in the weather, business, and sports pages, so why not the news?
crib deaths within a family are not independent,
conditional probability:
prob(A | B).
Boy or Girl paradox. People tend to say .5; the correct answer is .33.
“Did you see that poor disabled guy?
“Yeah, but his tailor is a genius—the suit fits him perfectly!”
The psychoanalyst Carl Jung proposed a mystical force called synchronicity to explain the quintessential thing that needs no explanation, the prevalence of coincidence in the world.
post hoc hanky-panky.
the cluster illusion.
if 23 people are in a room, the chances that two will share a birthday are better than even. With 57 in the room, the odds rise to 99 percent.
When a series of plagues is visited upon us, it does not mean there is a God who is punishing us for our sins or testing our faith. It means there is not a God who is spacing them apart.
Extraordinary claims require extraordinary evidence.
“Rationality Community,”
Suppose that the prevalence of breast cancer in the population of women is 1 percent. Suppose that the sensitivity of a breast cancer test (its true-positive rate) is 90 percent. Suppose that its false-positive rate is 9 percent. A woman tests positive. What is the chance that she has the disease? The most popular answer from a sample of doctors given these numbers ranged from 80 to 90 percent.3 Bayes’s rule allows you to calculate the correct answer: 9 percent.
posterior probability:
prior probability
likelihood.
commonness or ordinariness of the data.
she is representative of an art history major, and the stereotype crowds out the base rates.
Bayesian updating.
It’s simply the mindset of someone who wasn’t born yesterday.
The reason these studies were sitting ducks for the replicability snipers is that they had low Bayesian priors. Not as low as ESP, to be sure, but it would be an extraordinary discovery if mood and behavior could be easily pushed around by trivial manipulations of the environment.
The problem is that “surprising” is a synonym for “low prior probability,”
Forbidding the use of ethnic, sexual, racial, or religious base rates is a public commitment to equality and fairness
failure to think clearly about base rates—to lay out when there are good reasons for forbidding them and when there are not.
The problem is: which base rate?
