Wisdom of Crowds

Wisdom of crowds is the idea that large groups of people are collectively smarter than even individual experts when it comes to problem solving, decision making, innovating and predicting. The wisdom of crowds concept was popularized by James Surowiecki in his 2004 book, The Wisdom of Crowds, which shows how large groups have made superior decisions in pop culture, psychology, biology, behavioral economics and other fields.

The idea of the wisdom of crowds can be traced back to Aristotle’s theory of collective judgment as presented in his work Politics. He used a potluck dinner as an example, explaining that a group of individuals may come together to create a more satisfying feast for a group as a whole than what one individual might provide.

Here are two examples that show how the concept works.

1. By averaging together the individual guesses of a large group about the weight of an object, the answer may be more accurate than the guesses of experts most familiar with that object.

2. The collective judgment of a diverse group can compensate for the bias of a small group. In trying to guess the outcome of a World Series game, fans may be irrationally biased toward their preferred teams, but a large group that includes plenty of non-fans and individuals who dislike both World Series teams may be able to more accurately predict the winner.

Crowds aren’t always wise. In fact, some can be the opposite. Take, for instance, frenzied investors who participate in a stock market bubble like the one that occurred in the 1990s with dotcom companies. The group, or crowd, involved in this bubble invested based on speculation that internet startups would become profitable at some point in the future. Many of these companies’ stock prices soared, despite the fact that they had yet to generate any revenue. Unfortunately, a good portion of the companies went under, as panic ensued in the markets following mass sell orders on the stocks of some of the major tech companies. 

But, according to Surowiecki, wise crowds have several key characteristics. First off, the crowd should be able to have a diversity of opinions. Secondly, one person’s opinion should remain independent of those around them (and should not be influenced by anyone else). Next, anyone taking part in the crowd should be able to make their own opinion based on their individual knowledge. Finally, the crowd should be able to aggregate the individual opinions into one collective decision. 

The wisdom of crowds can also help explain what makes markets, which are a type of crowd, efficient at times and inefficient at others. If market participants are not diverse and if they lack incentives, then markets will be inefficient and an item’s price will be out of step with its value.

In a 2015 Bloomberg View article, wealth manager and columnist Barry Ritholtz argued that prediction and futures markets, unlike markets for goods and services, lack the wisdom of crowds because they do not have a large or diverse pool of participants. He points out that prediction markets failed spectacularly in trying to guess the outcomes of events such as the Greek referendum, the Michael Jackson trial, and the 2004 Iowa primary. The individuals trying to predict the outcomes of these events were simply guessing based on public polling data and did not have any special individual or collective knowledge.

While there is merit to the idea that the many are smarter than the few, it is not always true, particularly when members of the crowd are aware of and are influenced by each other’s ideas. Consensus thinking among a group of people with poor judgment can, unsurprisingly, lead to poor group decision making; this factor may have been one of the causes of the 2008 financial crisis. It can also explain why democracies sometimes elect unqualified leaders. In other words, as explained by British science writer Philip Ball in a 2014 article for the BBC, it matters who is in the crowd.