Is being your own crowd a wise move?
The wisdom of crowds operates by exploiting the diversity of views
Crowds of humans can be very good at solving certain kinds of problems. If, for example, you wanted to guess how many bacteria live in Lake Erie, you’d be better off asking a random group of people and averaging the result than trying to answer the question alone.
But what if you could be your own crowd by averaging your own guesses? Bizarrely, research suggests this can actually work.
The wisdom of crowds operates by exploiting the diversity of views. The technique has been used to improve economic forecasts, doctors’ decisions and weather predictions.
But we still have a lot to learn about how and when it works. It can go wrong if the people involved are all biased in similar ways or if one person’s choice influences others.
It works better if you ask people what they think and what they expect the popular opinion to be, and look for discrepancies between the two. This draws out the knowledge of informed subgroups.
So how about using crowd wisdom without a crowd, harnessing the different perspectives that one person brings to a question at different moments?
Psychologists have been testing the idea in small experiments for several years. Recently, researchers hit on a great source of data: three separate contests at a Dutch casino, each offering a prize of €100,000 to the person who could come closest to guessing the number of pearls held in an oversized champagne glass. About 160,000 people participated in each contest and were able to guess repeatedly over a two-month period.
The researchers — psychologists Dennie van Dolder of the University of Nottingham and Martijn van den Assem of the University of Amsterdam — found that errors tended to get smaller if people averaged out many guesses. The benefit grew with more guesses.
It wasn’t a matter of people learning over time — say, by consulting with others. Later guesses showed no significant improvement in accuracy. It was only the average that became more accurate.
The research offered some insights into how individuals can improve their performance. Estimates were better, for example, when people took more time between guesses.
This might help them have different thoughts or forget their previous line of thinking, increasing the independence of subsequent guesses and enhancing the diversity that makes crowd wisdom work.
Considering a problem from as many angles as possible is a common habit of intelligent people
Earlier studies, using much less extensive data, found something similar: accuracy improves if people are encouraged to make estimates in different ways, using different evidence and strategies. It is a process psychologists call "dialectical bootstrapping".
Of course, considering a problem from as many angles as possible is a common habit of intelligent people and those who make good decisions.
Even so, you won’t become a genius by drawing on your inner crowd. The casino study found that people’s biases still led them astray, accounting for about 50% of the overall error in their guesses. No number of guesses can fix that, as they all come from the same biased person.
So real crowds are still better. But guessing a dozen times can improve one person’s estimate by about 40%.
The same result can be achieved by averaging the guesses of two different people.
Although individuals can improve their performance, seeking the views of other people is still a lot better than trying to go it alone.
This is a bit of wisdom that people would do well to recognise: according to studies by psychologists, they still tend to stick too much to their own initial views.