A Strange Concept Such As Globability.
Mar. 16th, 2019 08:59 amTHE BOOKENING TITLE #18: Thinking, Fast and Slow, Daniel Kahneman.
A non-fiction book, for once!
This is about how our brains make decisions, the shortcuts they take, the pitfalls they're prone to, and it's probably the most interesting book I've ever read. I've always been interested in logical fallacies, heuristics and so on, but I think this is the best work I've encountered on the subject.
A few points I found particularly interesting:
- pp.117-118: on account of research showing that a disproportionate number of the best-performing schools are small, a lot of money and effort has gone into creating small schools or splitting up larger schools in the US. As it happens, a disproportionate number of the worst-performing schools are also small. Small schools aren't inherently better; their performance is just more likely to skew away from the average, because there are fewer data points involved. If you flip a coin four times, you're way more likely to get 100% or 75% heads than if you flip it fifty times.
- pp.43-44, on a study of eight parole judges in Israel: They spend entire days reviewing applications for parole. The cases are presented in random order, and the judges spend little time on each one, an average of 6 minutes. (The default decision is denial of parole; only 35% of requests are approved.) ... The authors of the study plotted the proportion of approved requests against the time since the last food break. The proportion spikes after each meal, when about 65% of requests are granted. During the two hours or so until the judges' next feeding, the approval rate drops steadily, to about zero just before the meal. As you might expect, this is an unwelcome result and the authors carefully checked many alternative explanations. The best possible account of the data provides bad news: tired and hungry judges tend to fall back on the easier default position of denying requests for parole.
- pp.125-126, on how we'll be influenced by any number that comes to mind when making estimates or other numerical decisions: The power of random anchors has been demonstrated in some unsettling ways. German judges with an average of more than fifteen years of experience on the bench first read a description of a woman who had been caught shoplifting, then rolled a pair of dice that were loaded so every roll resulted in either a 3 or a 9. As soon as the dice came to a stop, the judges were asked whether they would sentence the woman to a term in prison greater or lesser, in months, than the number showing on the dice. Finally, the judges were instructed to specify the exact prison sentence they would give to the shoplifter. On average, those who had rolled a 9 said they would sentence her to 8 months; those who rolled a 3 said they would sentence her to 5 months.
(This isn't terribly important, but I cannot get my head around how a pair of dice, assuming they're six-sided, can be loaded so every roll will result in either a three or a nine. Three or eight would be possible: you rig them so one always lands on two and the other can land on either one or six. Three or nine, though? I don't think it can be done. Maybe there were multiple pairs?)
- pp.175-176, on regression to the mean: the author once gave a talk to some air force flight instructors on how reward was more effective than punishment. One instructor objected, saying that cadets generally performed worse after he praised them and better after he screamed at them. But their performance would probably have changed regardless: Naturally, he praised only a cadet whose performance was far better than average. But the cadet was probably just lucky on that particular attempt and therefore likely to deteriorate regardless of whether or not he was praised. Similarly, the instructor would shout into a cadet's earphones only when the cadet's performance was unusually bad and therefore likely to improve regardless of what the instructor did.
- p.329, on the tendency to look at numbers alone and ignore what they're relative to: In one study, people who saw information about 'a disease that kills 1,286 people out of every 10,000' judged it as more dangerous than people who were told about 'a disease that kills 24.14% of the population.' The first disease appears more threatening than the second, although the former risk is only half as large as the latter! In an even more direct demonstration of denominator neglect, 'a disease that kills 1,286 people out of every 10,000' was judged more dangerous than a disease that 'kills 24.4 out of 100.'
I enjoyed this book a lot, and it's worth checking out if you're interested in the weirdness of the human brain.
A non-fiction book, for once!
This is about how our brains make decisions, the shortcuts they take, the pitfalls they're prone to, and it's probably the most interesting book I've ever read. I've always been interested in logical fallacies, heuristics and so on, but I think this is the best work I've encountered on the subject.
A few points I found particularly interesting:
- pp.117-118: on account of research showing that a disproportionate number of the best-performing schools are small, a lot of money and effort has gone into creating small schools or splitting up larger schools in the US. As it happens, a disproportionate number of the worst-performing schools are also small. Small schools aren't inherently better; their performance is just more likely to skew away from the average, because there are fewer data points involved. If you flip a coin four times, you're way more likely to get 100% or 75% heads than if you flip it fifty times.
- pp.43-44, on a study of eight parole judges in Israel: They spend entire days reviewing applications for parole. The cases are presented in random order, and the judges spend little time on each one, an average of 6 minutes. (The default decision is denial of parole; only 35% of requests are approved.) ... The authors of the study plotted the proportion of approved requests against the time since the last food break. The proportion spikes after each meal, when about 65% of requests are granted. During the two hours or so until the judges' next feeding, the approval rate drops steadily, to about zero just before the meal. As you might expect, this is an unwelcome result and the authors carefully checked many alternative explanations. The best possible account of the data provides bad news: tired and hungry judges tend to fall back on the easier default position of denying requests for parole.
- pp.125-126, on how we'll be influenced by any number that comes to mind when making estimates or other numerical decisions: The power of random anchors has been demonstrated in some unsettling ways. German judges with an average of more than fifteen years of experience on the bench first read a description of a woman who had been caught shoplifting, then rolled a pair of dice that were loaded so every roll resulted in either a 3 or a 9. As soon as the dice came to a stop, the judges were asked whether they would sentence the woman to a term in prison greater or lesser, in months, than the number showing on the dice. Finally, the judges were instructed to specify the exact prison sentence they would give to the shoplifter. On average, those who had rolled a 9 said they would sentence her to 8 months; those who rolled a 3 said they would sentence her to 5 months.
(This isn't terribly important, but I cannot get my head around how a pair of dice, assuming they're six-sided, can be loaded so every roll will result in either a three or a nine. Three or eight would be possible: you rig them so one always lands on two and the other can land on either one or six. Three or nine, though? I don't think it can be done. Maybe there were multiple pairs?)
- pp.175-176, on regression to the mean: the author once gave a talk to some air force flight instructors on how reward was more effective than punishment. One instructor objected, saying that cadets generally performed worse after he praised them and better after he screamed at them. But their performance would probably have changed regardless: Naturally, he praised only a cadet whose performance was far better than average. But the cadet was probably just lucky on that particular attempt and therefore likely to deteriorate regardless of whether or not he was praised. Similarly, the instructor would shout into a cadet's earphones only when the cadet's performance was unusually bad and therefore likely to improve regardless of what the instructor did.
- p.329, on the tendency to look at numbers alone and ignore what they're relative to: In one study, people who saw information about 'a disease that kills 1,286 people out of every 10,000' judged it as more dangerous than people who were told about 'a disease that kills 24.14% of the population.' The first disease appears more threatening than the second, although the former risk is only half as large as the latter! In an even more direct demonstration of denominator neglect, 'a disease that kills 1,286 people out of every 10,000' was judged more dangerous than a disease that 'kills 24.4 out of 100.'
I enjoyed this book a lot, and it's worth checking out if you're interested in the weirdness of the human brain.
