Moriah Waterland's Weblog

Friday August 26, 2005

My tipping point I finished reading "The Tipping Point" by Malcolm Gladwell last week. Although, I found some of the topics in the book interesting, in general I felt frustrated with what I perceived to be a lack of completeness with some of the author's theories. My tipping point from frustration to flat out irritation came with the following example. In this example the author attempts to reference research by Leda Cosmides into human cognition and the effects of context.

     Suppose four people are drinking in a bar.  One is drinking Coke. One is sixteen. One is drinking beer and one is twenty-five. 
     Given the rule that no one under twenty-one is allowed to drink beer, which of those people's IDs do we have to check to make
     sure the law is being observed? ("The Tipping Point", MG, pg159)

Hmm, well, assuming that the one who is drinking Coke is only drinking coke, then I would have to go with the one who is drinking beer, as they are the only individual drinking beer, whose age is unknown. But, wait..there's more! Lets see what Mr. Gladwell's answer is:

     Now the answer is easy. In fact, I'm sure that almost everyone will get it right: the beer drinker and the sixteen-year-
     old. ("The Tipping Point", MG, pg160)

Wow, don't I feel like an addlepated infant! The sixteen-year-old? Are you sure? But don't we already know how old they are? How would it be useful to check their ID? Wouldn't it be more constructive to check what they are drinking?
*sigh*
If an author doesn't feel like paying attention to details, then it would be nice if they could at least refrain from using statements like "Now the answer is easy" or "almost everyone will get it right". (2005-08-26 10:50:13.0) Permalink Comments [8]

Comments:

http://www.duboislc.net/math/BrainTeaser.html

Posted by 24.8.49.15 on October 01, 2005 at 02:29 AM MDT #

Found your site searching just the same issue. Bravo!

Posted by Clayton on November 09, 2005 at 01:46 PM MST #

Hi Moriah,
You're answer is correct and the author's is not. The author is flat out wrong.

The question of the puzzle is, "which of those people's IDs do we have to check to make sure the law is being observed?" We are given as a fact that one of them is 16 years old. If we check their ID, we get no new information to let us know if the law is being upheld.

On the other hand, if the puzzle question was, "which of those people's IDs and drinks do we have to check to make sure the law is being observed?", then the book's/author's answer would be ok.

Posted by Jason Harris on June 28, 2006 at 04:32 PM MDT #

I'm most of the way through "Tipping Point" and I'm pretty annoyed by it. I'm reading it after having gone through "Wisdom of Crowds" and "Freakenomics"

Basically, I get the overall sense that Gladwell, who studied history, is trying to "fit in" with the scientist community (which includes his mother and father). Problem is, he just isn't smart enough nor informed enough to do so.

Perhaps he should have written a book on history.

The incorrect logic puzzle described above (and the pure numbers version with the odd/even cards, which is also wrong) sent me off a wall as well.

In fairness, though, I will state that his _point_ was valid, even if his logic puzzle was not.

"Freakenomics" and "Widom of Crowds" are, by the way, fantasic books.

-Alan

Posted by Alan on August 06, 2006 at 10:57 AM MDT #

Yes, Gladwell butchers the exercise by saying you are going to "check the ID." It should actually be "which patron(s) should you check out," or "investigate" or any other phrase that suggests checking the age _or_ the beverage.

I believe Cosmides actually presented it correctly. And presented correctly, it really does make her point -- the bar version can be answered correctly off the top of the head by most people, the letter/number version seems to require more careful thought, and trips many people up. Yet they are the same problem.

Ahem. Presented correctly.

Posted by Bill Adams on November 14, 2009 at 01:43 AM MST #

I found the book fascinating, but wanted to do some fact checking. Since this puzzle was self-contained (i.e., I didn't need to look elsewhere for anything to verify), I started there. Unfortunately, I found it to be mistaken.

What first caught my attention was my thinking, "Why would it make sense to check the ID of the person whom we already know is too young to drink beer? Why would someone lie about his age and say he's NOT old enough to drink?"
Then I realized that checking his ID tells you nothing you don't already know. In fact, you could check all four IDs and still not know if the law was being violated.

It certainly casts a pall of doubt over the other facts cited in the book.
I'd be interested in hearing if anyone has done any fact checking on other things cited by Gladwell, and what the results were.

Posted by Barry on November 15, 2009 at 01:23 PM MST #

ps - Like Clayton, I found this site because I was searching the Web to see if anyone else had found the same error.

Posted by Barry on November 15, 2009 at 07:25 PM MST #

I'd like to point out to Alan that the "pure numbers" version IS correct in the book (unlike the bar and beer version).

Posted by Barry on November 19, 2009 at 04:14 PM MST #