On matters of general knowledge, quantity estimation, and spatial reasoning, an aggregated answer from a large group is often better than a single answer from an individual, even one supplied by a supposed "expert." This peculiar phenomenon is commonly known as the "wisdom of the crowd."
An early example of such collective insight originated from English polymath Sir Francis Galton. Very much an elitist, Galton believed that the mindless masses could not be trusted to make important decisions or, honestly, do much of anything. One day, as he was strolling through a local county fair, Galton came across a competition where individuals were attempting to guess the weight of a cow. The lucky person who guessed the cow's weight (after it had been slaughtered and dressed) would win the meat of the butchered bovine. In total, 800 people privately submitted their guesses on tickets.
Seeking statistical evidence to substantiate his haughty notions that common crowds couldn't correctly determine anything, Galton borrowed the tickets from the organizer at the conclusion of the competition. He presumed that the aggregated guesses wouldn't be remotely close to the actual weight of the cow.
How wrong he was.
As it turned out, the mean of the crowd's guesses was remarkably near to the actual answer, much closer, in fact, than any of the individual guesses. The collective guess was 1,197 pounds, while the actual weight of the animal after being butchered was 1,198!
Since Galton's discovery, other examples of the wisdom of the crowd effect have been documented scientifically and anecdotally. Most involve guessing the amount of jellybeans in a jar. The effect is also on display in Who Wants to Be a Millionaire's "ask the audience" lifeline, which, amazingly, is correct over 90% of the time.
But beyond winning game shows, sating sweet tooths, and appraising weight, can the wisdom of the crowd effect be harnessed effectively to make important, practical decisions, such as electing politicians?
My guess (albeit a solo one) is no, at least not in the purest terms.
In his book, The Wisdom of the Crowds, author James Surowiecki describes four key criteria that separate wise crowds from dysfunctional ones. They are:
Diversity of Opinion - Each person should have private information even if it's just an eccentric interpretation of the known facts.
Independence - People's opinions aren't determined by the opinions of those around them.
Decentralization - People are able to specialize and draw on local knowledge.
Aggregation - Some mechanism exists for turning private judgments into a collective decision.