Chad Perrin: SOB

24 November 2007

the wisdom of crowds

Filed under: Cognition — apotheon @ 07:09

There's no such thing as a "wisdom of crowds". That may sound funny, coming from a former Wikimedia Foundation employee and current Wikipedia/Wikinews proponent like me, but it's true. It's not "the wisdom of crowds" that makes Wikipedia work, but the ability to aggregate individual knowledge and save it in a central location.

Collecting people in crowds increases exactly three things with any certainty, and none of them are wisdom:

  1. It increases the likelihood of a single individual member of the crowd surviving against predators.
  2. It increases the effective conservatism of decision-making, not only when consensus (or even majority) decisions are made, but often even individual decisions.
  3. It increases the tendency of individuals within the crowd to excuse their own actions and justify them regardless of how reprehensible those actions may be when contemplated in solitude.

At this moment in time, for me at least, the most interesting of the three is point two — because it implies something quite contrary to the "wisdom of crowds" nonsense people keep yammering on about. Crowds are not wise. The wisdom of a crowd, if anything, is probably roughly equal to the wisdom of its least wise member minus the cube of the number of individuals in the crowd, or something along those lines — assuming wisdom is quantifiable.

The plummeting sense of accountability amongst members of a mob (aka "crowd") as it grows larger is also somewhat indicative of a distinct lack of wisdom.


  1. It's nice to see IT people catching on to what a lot of social scientists have known for decades. The "wisdom of the crowds" is a book selling device and feel-good theory, but it is not reality. As you say, "the crowds" are really a collection of individuals making individual decisions. I do not recall ever hearing an evolutionary behaviorlist, game theorist, or anyone else who is knowledgeable about these topics tout this pap. It is reserved for psuedo-scientific types like Malcolm Gladwell who claim to change paradigms just because they found some anecdotes that challenge mainstream canon on the topic.

    Indeed, the mob mentality is a great example. If 100 different people show up to protest in from of City Hall on the same day, a riot might break out. If the same 100 people show up as individuals over the course of 100 days, they are a peaceful string of people with signs. It is amazing how the whole can become more (or less) than the sum of the parts, and often not in a good way.


    Comment by Justin James — 30 November 2007 @ 09:11

  2. I've basically had this opinion since the very first time I heard that insipid phrase — "the wisdom of crowds". As I experience more, and encounter more evidence of how "the wisdom of crowds" works, I find that opinion only strengthened.

    People sometimes refer to "the wisdom of crowds" in reference to the success of Wikipedia, as if getting large numbers of people together magically produces wonders. The truth is that a project like Wikipedia involves careful planning, vigilance, and a hell of a lot of work, to say nothing of ingenuity and a tendency to be able to fit process to the realities of economic and game theory.

    Comment by apotheon — 3 December 2007 @ 06:28

  3. Yes, that phrase likewise makes me shudder. I love it when folks try to apply it to open source. What makes open source work most certainly is not the "wisdom of the crowds".


    Comment by Justin James — 3 December 2007 @ 08:02

  4. [...] The unwisdom of crowds. [...]

    Pingback by Chipping the web - aleph to taw -- Chip’s Quips — 5 December 2007 @ 12:46

  5. I'm not sure if applying the theory of the "wisdom of crowds" to Wikipedia is correct or not but I'm wondering if any of you have actually read James Surowiecki's book and would care to comment on that.

    Comment by therollingstone — 16 December 2007 @ 03:11

  6. I've read Surowieki's book, and found it quite interesting. In it, he looks at several places where the crowds are definitely not wise as well as where they are. The three statements above are also interesting and may be true in some circumstances, but at least Surowieki gives evidence for his arguments! Personally, I think that there is power in mob mentality and where there is power there is also the possibility to be wise – look at at Live Aid perhaps?

    Comment by Jem Mackay — 18 December 2007 @ 11:28

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