It's apparently a Terry Pratchett quote: "The intelligence of that creature known as a crowd is the square root of the number of people in it."
A sixteen-year-old newsgroup poster explains it as follows:
> Sorry to disagree, but I thought the quote worked extremely well the first
time and on further reflection, still do. I think it's very apt and I would
hesitate to say that perhaps you didn't see the intended purpose on first
reading.
> Terry talks about the crowd as a creature, therefore implying one single IQ.
So, to use your own methods, let's say a crowd of 100 people would have an
IQ of 10 - not each, but altogether. Each person would have an IQ of 0.1
if you wanted to break it down, although to do so would be completely
counter-productive, because we are talking about a crowd and not a single
person. Once you start talking about single people, they are no longer part
of the crowd and their IQ would revert to normal status. The crowd is a
whole, and the description provides a picture of it being a single organism
with one purpose (to imply the fervour that people get swept up in, in
crowds, e.g. race riots, Paedophile lynchings, vigilantes that one person
would not do)
> I think the purpose behind the description was to provide the metaphor of a
crowd being a big, dumb, violent animal composed of intelligent, reasoning
people - a sort of paraphrase on "the sum is greater than the parts".
As an aside, I find it amazing that I was able to go from a paraphrased description of a quote to an in depth discussion of the accuracy of the quote with suggestions for alternative functions. Despite all its flaws, the hacks upon hacks upon hacks we call the internet is incredible when you step back and consider it all.
An interesting idea, but taken literally, it implies that any crowd larger than 22,500 people (150^2) has genius-level intelligence, which is kind of laughable.
The lower boundary of the 99 percentile goes up as 1/sqrt(N) and approaches the average member intelligence, but never reaches that level. At the same time, the upper boundary of the 99 percentile goes down at the same speed. However the number of super smart members, with IQ higher than say 160, grows linearly.
I agree completely, and I doubt Pratchett conducted much research to derive that algorithm. He might even be wrong about the constant factor at lower levels.
A sixteen-year-old newsgroup poster explains it as follows:
> Sorry to disagree, but I thought the quote worked extremely well the first time and on further reflection, still do. I think it's very apt and I would hesitate to say that perhaps you didn't see the intended purpose on first reading.
> Terry talks about the crowd as a creature, therefore implying one single IQ. So, to use your own methods, let's say a crowd of 100 people would have an IQ of 10 - not each, but altogether. Each person would have an IQ of 0.1 if you wanted to break it down, although to do so would be completely counter-productive, because we are talking about a crowd and not a single person. Once you start talking about single people, they are no longer part of the crowd and their IQ would revert to normal status. The crowd is a whole, and the description provides a picture of it being a single organism with one purpose (to imply the fervour that people get swept up in, in crowds, e.g. race riots, Paedophile lynchings, vigilantes that one person would not do)
> I think the purpose behind the description was to provide the metaphor of a crowd being a big, dumb, violent animal composed of intelligent, reasoning people - a sort of paraphrase on "the sum is greater than the parts".
https://alt.books.pratchett.narkive.com/nVL49SnZ/quote-from-...
As an aside, I find it amazing that I was able to go from a paraphrased description of a quote to an in depth discussion of the accuracy of the quote with suggestions for alternative functions. Despite all its flaws, the hacks upon hacks upon hacks we call the internet is incredible when you step back and consider it all.