The quiz Daniel Kahneman wants you to fail • Hacker News Board

Re: The quiz Daniel Kahneman wants you to fail

#111

Post by SilasX » Fri, Jan 06, 2012, 4:42 PM UTC

tikhonj wrote: post #38

Not exactly the same, but my favorite visceral examples of imperfect heuristics are "garden-path sentences"[1]. These are sentences that trick you into having to backtrack when you're parsing them, which brings the whole parsing process into sharp relief. [1]: http://en.wikipedia.org/wiki/Garden_path_sentence A good example is: The old man the boat. Figure out why this sentence is actually grammatically valid and the…

To save everyone the trouble of reading a lot to learn a little: "man" is a verb in that sentence.

Though if I wanted to be clever I could hammer that into less garden-pathy sentence as follows:

"In my will, I left everything to the one who could use it best. I gave the boy the legos. I gave the girl the dollhouse. I gave the mother the kitchen set. The father the hunting rifle. The bachelor the suit. The old man the boat."

Re: The quiz Daniel Kahneman wants you to fail

#112

Post by prof_hobart » Fri, Jan 06, 2012, 4:52 PM UTC

condiment wrote: post #104

prof_hobart wrote: post #86

Earlier quoted context omitted.

It's not that a lawyer can't like maths or dislike politics. The issue is whether they are less likely to on average. From my personal experience of knowing several of both groups, I would say that on average the lawyers I know are less interested in maths than the engineers and more interested in politics than them. It doesn't apply universally (some of the engineers I know are obsessed by politics, just not all of…

I think the point that many are missing is that is not known for certain that an engineer is more likely to enjoy certain hobbies over others. People use their personal experience to develop a heuristic which this test is designed to reveal. Getting hung up over the specificity of the hobbies and interests and the likelihood of those hobbies and interests representing either or a lawyer or an engineer is irrelevant,…

It's not "getting hung up" about the specifics. They are relevant, and clearly deliberately chosen. You're right that we don't know this likelihood with absolute 100% certainty, but that doesn't mean we should dismiss our personal experience, and a bit of logic (maths is typically more useful for, and a more practical path into, engineering than law, and there's far more politicians in my country with a background in law than there are with a background in engineering) out of hand.

What this article is trying to present is heuristic errors - like question 1, where ignoring of the fact that sample size is relevant gets you to the wrong answer. Ignoring the likelihood that there is a correlation between personal interests and career choice seems to me to be the equivalent heuristic error for this question.

Let me give you an alternate example. There are roughly 700 million Europeans and roughly 300 million Americans. If I randomly picked one person out from this, gave you no other information and asked you where they came from, you'd have a 70% chance of guessing correctly by saying "Europe". If I told you that their first language was English, that they loved American football and baseball and hated soccer, and that their favourite TV show was Conan, and then asked you to guess where they came from, it would be hugely naive to ignore that information and still assume that they were probably European. Yes, it's entirely possible that there are Europeans who fall into all of those things, and I've not done a survey to find the exact percentage of each group that answer this description, but I'd be prepared to put a fair amount of money on the fact that there's a larger overall number of Americans who answer it than Europeans, so the smart guess would now be that they are American.

Re: The quiz Daniel Kahneman wants you to fail

#113

Post by kstenerud » Fri, Jan 06, 2012, 4:53 PM UTC

Their interpretation of question 5 is just plain wrong. Aside from the fact that losses DO hurt more than gains (because you need to alter your plans to accomodate losses), the assumption of equivalence is fundamentally flawed.

The problem is that the two halves are inverted. Correcting:

5a: Your base position is $900, and you have the option of risking $900 for a possible gain of $100. You have a 90% chance of gaining $100 (a trivial amount) and a 10% chance of losing $900 (a big amount).

5b: Your base position is -$900, and you have the option of risking $100 for a possible gain of $900. You have a 90% chance of losing $100 (a trivial amount) and a 10% chance of gaining $900 (a big amount).

Since you're an individual, and not a statistical average, there's no middle ground in the values gained or lost. So the rational person is right to choose A, then B. The two are NOT equivalent to an individual. The trivial amount makes little difference as a gain or a loss, but the big amount does.

Re: The quiz Daniel Kahneman wants you to fail

#114

Post by andylei » Fri, Jan 06, 2012, 5:11 PM UTC

colanderman wrote: post #23

The questions involving "90% chance of $1000 or 100% chance of $900" always bother me. I never understand why economists think that a rational actor would consider them equivalent; they're not , unless you are making that choice many many times. But if I'm given that chance once (which is presumably what most participants assume, since that's not a choice that comes up often in one's life), it's really then a choice…

the actual question is wrong. to illustrate the framing effect, which underlies prospect theory, the question should be:

1. choose a) 90% for $1000 or b) 100% for $900 a. you just got $1000. choose a) 10% chance to loose $1000 or b) 100% chance to loose $100.

according to rational actor theory, people should choose the same thing both times. however, people often don't. its the framing effect. decisions are different when framed as losses or games.

this builds the foundation for prospect theory. rational actor theory says that your preferences are consistent. prospect theory says that you have a reference point and your utility function is inconsistent and changes depending on your reference point.

Re: The quiz Daniel Kahneman wants you to fail

#115

Post by Someone » Fri, Jan 06, 2012, 8:57 PM UTC

Vivtek wrote: post #9

I didn't much like this: " being swayed by the way in which questions are worded rather than responding just to their substance " (for the lost ticket being allegedly equivalent to $10). Is a ticket, which costs $10, emotionally equivalent to $10? Once bought, the ticket is unique in my eyes, whereas I'm not even sure how many $10 bills I have in my wallet even now. So if I lose one, well, maybe it wasn't there in th…

What I found weird about at case is that it did not consider the investment made by going to the theater. The time spent to go to the theater will be significant relative to that $10 ticket. And that is even ignoring travel and parking costs, and the fact that, by going to the theatre, you cut out other options of spending the night.

Because of that, I think most people would buy a new ticket.

Re: The quiz Daniel Kahneman wants you to fail

#116

Post by joemoon » Sat, Jan 07, 2012, 1:32 AM UTC

andylei wrote: post #114

colanderman wrote: post #23

The questions involving "90% chance of $1000 or 100% chance of $900" always bother me. I never understand why economists think that a rational actor would consider them equivalent; they're not , unless you are making that choice many many times. But if I'm given that chance once (which is presumably what most participants assume, since that's not a choice that comes up often in one's life), it's really then a choice…

the actual question is wrong. to illustrate the framing effect, which underlies prospect theory, the question should be: 1. choose a) 90% for $1000 or b) 100% for $900 a. you just got $1000. choose a) 10% chance to loose $1000 or b) 100% chance to loose $100. according to rational actor theory, people should choose the same thing both times. however, people often don't. its the framing effect. decisions are different…

Exactly. The OP's version can be described as these choices:

- A 10% chance of losing (you don't get any money).

- A 10% chance of winning (you don't lose any money).

These two are options are in no way equivalent. In your version, you have:

- 10% chance of losing (you don't get $1,000).

- 10% chance of losing (you have to pay $1,000).

These situations are comparable and can be used to test the framing effect.

Re: The quiz Daniel Kahneman wants you to fail

#117

Post by faboo » Sat, Jan 07, 2012, 1:49 AM UTC

colanderman wrote: post #96

2arrs2ells wrote: post #27

Earlier quoted context omitted.

The interesting thing is not that people are risk averse (and thus choose 100% chance of $900), the interesting thing is that people become risk seeking when it comes to losses (and thus choose 90% chance of -$1000). You're creating a bit of a straw man when it comes to behavioral economists and their view of "rational actors" - the whole field is built around the understanding that there is more to economic decision…

Ya, my theory holds for negative sums too -- I'd rather have a chance of not losing [large amount of money] than lose [almost as large amount of money] for sure. A $900 loss could be enough to bankrupt me -- I need to take the 10% chance.

The problem with that question, to me, is that the 10% difference in outcome is nearly inconsequential. By the time I'm losing (or gaining) $900, what's another $100? If the proportions were different, I think the question would be more interesting.

Re: The quiz Daniel Kahneman wants you to fail

#118

Post by mjwalshe » Sat, Jan 07, 2012, 2:42 AM UTC

Uhhrrr wrote: post #6

The engineer/lawyer problem explanation (spoilers) is only correct in a world where lawyers and engineers have all the same characteristics. That the sampled individual is a man will skew things all by itself. Of the lawyers, approximately 40% will be women, whereas only 11% of the engineers. So our samplee could be one of 27 engineers or 42 lawyers - we've already bumped Peng from .3 to .39! That he likes math puzzl…

And the killer mistake in # 2 is that he "He shows no interest in political and social issues" Now Law is inherently political (both big and small P's) even more so in the USA where Judges etc are elected.

I would bet good money that hes more likely an engineer than a lawyer.

Re: The quiz Daniel Kahneman wants you to fail

#119

Post by jacques_chester » Sat, Jan 07, 2012, 3:49 AM UTC

nkurz wrote: post #109

jacques_chester wrote: post #17

Earlier quoted context omitted.

I have to second this advice, even though I'm halfway through it. Kahneman has spent decades investigating biases and cognitive error. And it turns out he's not all that bad at popularising his and related research. Of particular fascination (and frustration!) are the little examples he liberally sprinkles throughout the book. Small quizzes, questions and the like for the reader to try. Try as I might, I have consist…

I'm halfway through it as well, but have a less positive impression. I came into it with a lot of respect for Kahneman and his research, but the first half of book is extremely flat. Much like the reaction here to this Vanity Fair teaser, I constantly find myself quibbling with the examples, and disagreeing with the explanations. I'm not sure who to blame, though. I think the book was written over a considerable peri…

I agree that the writing style is flat, but it's also very thorough and methodical. More than once I've found myself thinking "but what about X?" and then there, on the very next page, he addresses X to a depth I'd never considered.

The biggest counterargument against his tests is that like a lot of sentences, they can be read in more than one way. Possibly for people with System 2 minds that like to dissect concepts, that's enormously annoying.

Re: The quiz Daniel Kahneman wants you to fail

#120

Post by rwallace » Sat, Jan 07, 2012, 1:31 PM UTC

colanderman wrote: post #95

rwallace wrote: post #62

Earlier quoted context omitted.

A thousand dollars is not a life-changing sum. It's well within the range in which the utility of money is linear in the amount. (Even if it's large compared to what you have in your pocket, by the time you spend it, your life will be the same as it is now.) If we were talking about a million dollars, your answer would be right.

A thousand dollars is not a life-changing sum. There are many many people who would argue with that.

Such as? Even living below the poverty line in a poor country with soft currency (in which case you probably won't be reading HN or participating in psychology experiments) you're still likely to get through quite a bit more than that in a year.