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News & ArtsWednesday, June 13, 2012
Life / Science A Little Afternoon Reading on Cognitive Bias
Posted by Anna Minard on Wed, Jun 13, 2012 at 1:01 PM
More than 50 percent of Harvard, Princeton, and MIT students can't answer this question correctly:
A bat and ball cost a dollar and ten cents. The bat costs a dollar more than the ball. How much does the ball cost? (Answer here.)
Why? Science says: In some ways, the smarter you are, the stupider you are. Or something. Jonah Lehrer reports at his New Yorker blog series Frontal Cortex (seriously, if you'd like to lose an afternoon, get on that thing):
West and colleagues weren’t simply interested in reconfirming the known biases of the human mind. Rather, they wanted to understand how these biases correlated with human intelligence. As a result, they interspersed their tests of bias with various cognitive measurements, including the S.A.T. and the Need for Cognition Scale, which measures “the tendency for an individual to engage in and enjoy thinking.”
The results were quite disturbing. For one thing, self-awareness was not particularly useful: as the scientists note, “people who were aware of their own biases were not better able to overcome them.” This finding wouldn’t surprise Kahneman, who admits in “Thinking, Fast and Slow” that his decades of groundbreaking research have failed to significantly improve his own mental performance. “My intuitive thinking is just as prone to overconfidence, extreme predictions, and the planning fallacy”—a tendency to underestimate how long it will take to complete a task—“as it was before I made a study of these issues,” he writes.
4
Tellingly, I tried to shortcut it, failed, got mad, meekly did the basic, basic algebra, and didn't write the final steps when I realized the answer the algebra pointed me towards.
My notebook literally goes from
a+b=1.1
b=a+1
a+(a+1)=1.1
2a+1=1.1
a=$0.05
If I was patient, I would have written down all the steps-if I was confident off the bat, I would have written down none.
My notebook literally goes from
a+b=1.1
b=a+1
a+(a+1)=1.1
2a+1=1.1
a=$0.05
If I was patient, I would have written down all the steps-if I was confident off the bat, I would have written down none.
6
A certain water lily is growing in a lake, every day, the number of lilys doubles. On day one, there's 1 lily, on day two, there's 2 lilys, on day three, there's 4 lilys, and so on...
On day thirty, half the lake is filled. On what day will the lake be completely filled?
On day thirty, half the lake is filled. On what day will the lake be completely filled?
7
I put a dollar on the bat side, then divided the rest in two for each. Hence .10 /2 = .05 (+1 for the bat).
Not sure why this is so hard for people.
Not sure why this is so hard for people.
8
@7: As the article explains, it's because people take shortcuts, especially when they feel like they already know something.
9
@5
You'd be surprised, but not everybody visits Reddit, or relies on Reddit to get their intertron weblinks. It actually turns out that sometimes something that is popular in one corner of the internets is also popular in another, and got that way on its own.
You'd be surprised, but not everybody visits Reddit, or relies on Reddit to get their intertron weblinks. It actually turns out that sometimes something that is popular in one corner of the internets is also popular in another, and got that way on its own.
10
@9 - Count me as one. I can't stand Reddit, it's like following the entire English speaking world's Facebook feed.
13
I did it in my head visually like this:
one is a dollar more so it's at least a dollar.
duh, gee, that leaves ten cents.
then I "saw" the answer: a nickel, and $1.05.
one is a dollar more so it's at least a dollar.
duh, gee, that leaves ten cents.
then I "saw" the answer: a nickel, and $1.05.
15
@5: OMG. Someone posted something on a website that was already posted on another website. EPIC FAIL, dude!
16
I wish we knew more about our evolution. I think it would be easier to understand why we are what we are.
17
#7 nice
Most people do not think of balancing - which is, in fact, quite intuitive but still requires some thinking or at least looking
Most people do not think of balancing - which is, in fact, quite intuitive but still requires some thinking or at least looking
18
I get how the correct answer is correct, but I don't get how the obvious answer is wrong. 0.1 + 1 =1.1. A dollar and ten cents is a dollar more than ten cents as much as a dollar and five cents is a dollar more than five cents.
I got the lily pad question right from the original article. I had no trouble with Einsteins riddle the other day, but now I feel like an idiot. Is it reading comprehension? What am I missing?
I got the lily pad question right from the original article. I had no trouble with Einsteins riddle the other day, but now I feel like an idiot. Is it reading comprehension? What am I missing?
19
The bat and ball cost $1.10 *together*. Your solution of them being worth $1.10 and $.10 respectively would make them cost $1.20.
21
@19 I just realized that a dollar is only 90 cents more than .10 cents. Derp, as they say. Thanks for being kind in your correction.
22
Also from the New Yorker Article:
Perhaps our most dangerous bias is that we naturally assume that everyone else is more susceptible to thinking errors, a tendency known as the “bias blind spot.” This “meta-bias” is rooted in our ability to spot systematic mistakes in the decisions of others—we excel at noticing the flaws of friends—and inability to spot those same mistakes in ourselves
This strikes me as cultural. If he's interviewing people from expensive Ivy league schools, he's largely interviewing privileged, privately schooled elites that base their self worth on their intelligence. The blindness to personal bias would be linked to culture rather than intelligence. Harvard Princeton and MIT are not the first places I would go to find people that can be described as humble. Of course it could just be my class bias talking.
Perhaps our most dangerous bias is that we naturally assume that everyone else is more susceptible to thinking errors, a tendency known as the “bias blind spot.” This “meta-bias” is rooted in our ability to spot systematic mistakes in the decisions of others—we excel at noticing the flaws of friends—and inability to spot those same mistakes in ourselves
This strikes me as cultural. If he's interviewing people from expensive Ivy league schools, he's largely interviewing privileged, privately schooled elites that base their self worth on their intelligence. The blindness to personal bias would be linked to culture rather than intelligence. Harvard Princeton and MIT are not the first places I would go to find people that can be described as humble. Of course it could just be my class bias talking.
26
@16: The core reason behind most of these shortcuts is speed. In (extremely) broad terms, there are two key types of problem-solving methods: algorithms and heuristics. Generally speaking, an algorithm is a series precise steps that may take a while, but will get you an exact, correct answer. A heuristic is a series of estimates and shortcuts that works fast, and usually gets you a pretty close answer.
Your brain is wired up to work heuristically, rather than algorithmically. If you're walking through the jungle, and your brain sees a large cat with orange and black stripes, it doesn't behoove you to think "Based on the way that thing is moving, seemingly under its own power, I am 88% confident that it is an animal. Its movements correlate strongly with those of other animals that turned out to be apex predat-oh no I'm being eaten oh dear." It's much better for your brain to jump some steps, and say "Shit, tiger, run!"
If the heuristic is wrong sometimes, oh well, you ran away from some shadows. If the heuristic is too slow, you get eaten. Of course, in modern society, it's often more important to be right than to be fast, which is where we hit these problems.
Your brain is wired up to work heuristically, rather than algorithmically. If you're walking through the jungle, and your brain sees a large cat with orange and black stripes, it doesn't behoove you to think "Based on the way that thing is moving, seemingly under its own power, I am 88% confident that it is an animal. Its movements correlate strongly with those of other animals that turned out to be apex predat-oh no I'm being eaten oh dear." It's much better for your brain to jump some steps, and say "Shit, tiger, run!"
If the heuristic is wrong sometimes, oh well, you ran away from some shadows. If the heuristic is too slow, you get eaten. Of course, in modern society, it's often more important to be right than to be fast, which is where we hit these problems.
27
@ 21
DUDE!
I think you still might be right.
The guy who corrected you said, " Your solution of them being worth $1.10 and $.10 respectively would make them cost $1.20".
However, here is your solution: " 0.1 + 1 =1.1"
Monetary: $0.10 + $1.00 = $1.10
You never said that they were worth $1.10 AND another ten cents. What you did doesn't add up to $1.20. You added one dollar and ten cents.
So, it still seems to me that BOTH answers are correct. The weird thing is that was my initial guess before I saw the answer . . . so now I'm REALLY confused because the general consensus on this is that there's only one answer!!!
AAARGHH! MY BRAIN!
DUDE!
I think you still might be right.
The guy who corrected you said, " Your solution of them being worth $1.10 and $.10 respectively would make them cost $1.20".
However, here is your solution: " 0.1 + 1 =1.1"
Monetary: $0.10 + $1.00 = $1.10
You never said that they were worth $1.10 AND another ten cents. What you did doesn't add up to $1.20. You added one dollar and ten cents.
So, it still seems to me that BOTH answers are correct. The weird thing is that was my initial guess before I saw the answer . . . so now I'm REALLY confused because the general consensus on this is that there's only one answer!!!
AAARGHH! MY BRAIN!
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