There is an old saying that two heads are better than one. This saying received empirical support in social psychology in the 1920s, when a series of studies showed that groups were more accurate than their individual members. In an early demonstration of the phenomenon, for example, Columbia University’s Hazel Knight asked students to estimate the temperature in a classroom. When the estimates were averaged together, the resulting group answer was more accurate than the estimate of a typical member
Early authors found this surprising and attributed it to some mysterious group property. Eventually, however, it was recognized as a product of statistics: Using a large sample of imperfect estimates tends to cancel out extreme errors and converge on the truth. Subsequentresearch in forecasting demonstrated the power of averaging compared to more sophisticated statistical methods of combination. The power and simplicity of averaging was summed up in the title of James Surowiecki’s 2004 best-selling book, “The Wisdom of Crowds.”
In a fascinating new article in Psychological Science, Stefan Herzog and Ralph Hertwig turned the old aphorism on its head: One head can be nearly as good as two. Herzog and Hertwig had participants make estimates about quantitative values they did not know with certainty—specifically, dates in history. They then had participants make second estimates. Could this “crowd in the mind” help improve judgments? The answer is yes, and the literature on the wisdom of crowds helps us understand why.
Scientific American (Thanks KatM)
as we all think differently too we can mingle are ideas to come up with good ones.
Anyone read this book? Is it good? I love book recommendations, they’re my favourite, and I don’t have a ton left of Lucifer Effect.
It’s very good – it was on the best seller list of 2004. Check the link and read the reviews.
Well, Amazon gave it many stars and it just so happens that one of the local bookstores has two copies.
This blog always comes through when I am out of things to read. Good times!
Was staring at this on the shelf yesterday wondering whether I ought to read it or not. Got distracted last time.
@SGC – Do read ‘The Time Paradox’ also by Zimbardo. More info at http://www.thetimeparadox.com/ Will change the way you look at time. I have given up wearing my watch at weekends as a result of reading it.
I’m intending to buy ‘The Lucifer Effect’ with this month’s book money just as soon as I finish ‘The Luck Factor’ by Richard Wiseman http://www.amazon.co.uk/Luck-Factor-Scientific-Study-Lucky/dp/0099443244 also highly recommended.
I love you KatM (in a non creepy way). I can also get that one locally and now I really really want to, because Lucifer Effect is great and the timeparadox.com website looks really interesting. I’d like to read Luck Factor too, because Quirkology was awesome and might be on my list of top ten books ever.
Books fill my brain with information! I hope none of it falls out.
@SGC – Oooh nice to feel appreciated, thanks
This would probably go a way toward explaining how Wikipedia – for all its flaws – has been shown in studies (or a study, at least) to be as accurate as Britannica.
Neat! I’m so glad I read this (and the comments)!
Ofcourse 1 mind can see many things … be your own reviewer and review also the reviewer …
A crowd is not a standard … there are many factors that can influence the crowd’s focus/vision/its sane brain.
Temperature is also something we wont feel that accurate at all most of the time … we are not stable ourselves .. and will experience temperature in different states not the same all the time .. even when we are not sick, or doing hard physical labor. The power of the mind itself, can make you feel warmer or colder.
In serious groups it can work very well ofcourse … to get to even better results.
Nowadays we babble too much about those things I guess .. back then it was apparently not as normal .. or maybe it was already like that back then as well. Only scientists got published ofcourse .. we did not hear the crowd …….
I know the process of estimate, giving reasons for the estimate and then revising the estimate is used with groups as a forecasting method (Google or Wiki the Dephi method if you’re interested) but it’s interesting to see that it works with individuals.
Anyway, here’s a little related reading if you’re bored:
Nudge by Thaler and Sustein, Predictably Irrational by Ariely, Blink by Gladwell, Bounded Rationalty by Gigerenzer and Selton, The Black Swan by Taleb.
I should confess here before I look like a girly swot that I haven’t read all of these although I did pretend to someone the other day that I had so that I would look big and clever. Didn’t work
Estimation and Wisdom are not even in the same Dictionary (The two part OED that is) – the title is an ironic take on the 19th century work of social science “The Madness of Crowds and other popular delusions.” which examines the mob herd mentality behind the South Sea bubble and Tulipmania – in which the public invested heavily in dodgy ideas (think Sub-Primes today). As Derren has shown many times, crowds can get wrapped up in crazy ideas which as individuals they probably would think twice about. We want to believe that the crowd is right, it seems like democracy at work, but most of the most disastrous events in the modern world have been from consensus… (Nazism, ethnic cleansing, property boom’n'bust) whereas most of the great ideas have come from individuals (relativity, ipods, dual reality (ask DB)).
No no no. I need to believe that statistics are bullshit (for reasons I won’t go into).
@KatM ‘The Time paradox’ sounds good. Going to hunt it out tommorow. Thanks. Like anything to do with time.
x
Alfred Prufrock (without a ‘J’) interesting stuff but I’m not sure it’s quite that clear cut. From what I’ve read the problems with group thinking arise because of a desire or need to avoid within group conflct (Groupthink). However, groups can come up with great ideas provided criticism and debate are encouraged, for example the space shuttle. Just linking back to DB’s homeopathy post, this is why scientifc study of such issues should be trusted in general because the research is a mix of individual and group thinking that is then peer reviewed by panels of anonymous academics. It’s not perfect but it does minimise effects of Groupthink and other such cognitive biases.
Julie, its not statistics that are the problem, it’s the doughnuts who interpret them and then tell you a load of bullshit that are the problem
Apologies if I sound like I’m on my soapbox but I do find this stuff fascinating.
The wisdom of crowds vs the stupidity of the mob.
Discuss (30points)
While it is true that a measured average of individuals in a group will give an accurate reading, let’s not forget that people will walk past an empty restaurant to queue at mcdonalds.
When studied discretely, the opinions may illuminate, when viewed as a herd mind the actions will probably dissapoint.
U2 and coldplay are vying for title of biggest band in the world.
Ladies and gentlemen – this is the wisdom of crowds.
Happy now?
Google is dependent upon wisdom of crowds principles and we use the stupidity of this to exploit it !
Alfred Prucock – you are the wisdom of the individual – group think is for sheep!
http://www.the-system.org
does anybody else find this theory kind of states the obvious?
I would have thought that in the 1920′s scientists would have realised this is result of pure statistics.
Also (in my own understanding at least) this surely can only work if every individual in the group had some kind of prior knowledge or understanding of the subject matter.
Some examples are predicting the temperature in the room and, of course, guessing the weight of an ox.
A random event that is purely random (NOT based on prior events or the functionality of the system) cannot be predicted by an individual or group (using this method at least).
By finding the mean result, the extreme guesses can be cut out and the final result refined.
The closer to infinity the size of the group, the more accurate the final result.
@Journo julz
Perilously close to politics there julz!
Have you seen \”Century of the Self\” (BBC)?
Could be interesting if not….
From wartime propaganda & Freud, to Edward Bernaise, the birth of PR & consumerism, to New Labour (and everything in between).
http://video.google.com/videoplay?docid=8953172273825999151#