Knowledgeable individuals protect the wisdom of crowds
If you ask someone to guess the number of sweets in a jar, the odds that they’ll land upon the right number are low – fairground raffles rely on that inaccuracy. But if you ask many people to take guesses, something odd happens. Even though their individual answers can be wildly off, the average of their varied guesses tends to be surprisingly accurate.
This phenomenon goes by many names – swam intelligence, wisdom of the crowd, vox populi, and more. Whatever it’s called, the principle is the same: a group of people can often arrive at more accurate answers and better decisions than individuals acting alone. There are many examples, from counting beans in a jar, to guessing the weight of an ox, to the Ask The Audience option in Who Wants to be a Millionaire?
But all of these examples are somewhat artificial, because they involve decisions that are made in a social vacuum. Indeed, James Surowiecki, author of The Wisdom of Crowdsauthor of The Wisdom of Crowds, argued that wise crowds are ones where “people’s opinions aren’t determined by the opinions of those around them.” That rarely happens. From votes in elections, to votes on social media sites, people see what others around them are doing or intend to do. We actively seek out what others are saying, and we have a natural tendency to emulate successful and prominent individuals. So what happens to the wisdom of the crowd when the crowd talks to one another?
Andrew King from the Royal Veterinary College found that it falls apart, but only in certain circumstances. At his university open day, he asked 82 people to guess the number of sweets in a jar. If they made their guesses without any extra information, the wisdom of the crowd prevailed. The crowd’s median guess was 751.* The actual number of sweets was… 752.
This collective accuracy collapsed if King told different groups of volunteers about what their peers had guessed. If they knew about the previous guess, a random earlier guess or the average of all the earlier guesses, they overestimated the number of sweets. Their median guesses ranged from 882 to 1109. King likens this effect to real-world situations where people collectively drive the prices of items above their value and create economic bubbles. It’s what happened to create the recent US/British housing market crash or, more historically, the tulip mania of 17th century Holland.
Jan Lorenz recently found the same thing. Swiss college students can form a wise crowd when answering questions independently, but once they could find out what their peers had guessed, their answers became more inaccurate. In his summary of the study, Jonah Lehrer wrote, “The range of guesses dramatically narrowed; people were mindlessly imitating each other. Instead of canceling out their errors, they ended up magnifying their biases, which is why each round led to worse guesses.”
Is the crowd doomed to groupthink? Not quite. King found that he could steer them back towards a wiser guess by giving them the current best guess. When this happened, the median returned to a respectable 795. So the crowd loses its wisdom when it gets random pieces of information about what its members think, but it regains its wisdom if it finds out what the most successful individual said.
King says that this mirrors what happens in real life. The crowd may be a social beast, but it isn’t an indiscriminate one. Certain individuals wield disproportionate influence, and groups of soldiers, employees, players and even animals often rely on leaders when they make decisions.
There’s a reason for this. When King provided his volunteers with the best previous guess, their range of answers was narrower with fewer extreme predictions. Their collective answers were also about as accurate in small groups of 10 people as they were in larger ones of 70. King writes, “Copying successful individuals can enable accuracy at both the individual and group level, even at small group sizes.”
But King’s study still reflects an artificial situation, because he knew beforehand what the right answer was and could provide the crowd with the closest guess. Real crowds rarely, if ever, have that luxury. If anything, this results simply reiterates how important it is to choose who we emulate. If we pick poorly (like the crowds who learned about a random earlier guess), our decisions are worse. If we pick well (like the ones who learned about the best previous guess), we fare better. You can insert your own modern case study here, but perhaps this study ends up being less about the wisdom of the crowd than a testament to the value of expertise. Maybe the real trick to exploiting the wisdom of the crowd is to recognise the most knowledgeable individuals within it.
* Yes, I’m using the median. The last time a science writer did this for a wisdom-of-crowds story, the internet erupted. For anyone not convinced by the median, this post by Josh Rosneau lays it all out clearly. Stats junkies can pore over the data for themselves in the image below.
Reference: King, Cheng, Starke & Myatt. 2011. Is the true ‘wisdom of the crowd’ to copy successful individuals? Biology Letters http://dx.doi.org/10.1098/rsbl.2011.0795
Image from despair.com
Related Topics
Go Further
Animals
- These 'trash fish' are among Earth's most primitive animalsThese 'trash fish' are among Earth's most primitive animals
- These photos are works of art—and the artists are bugsThese photos are works of art—and the artists are bugs
- The epic migration of a 6-foot long, 200-pound catfishThe epic migration of a 6-foot long, 200-pound catfish
- Frans de Waal, biologist who studied animal emotion, dies at 75Frans de Waal, biologist who studied animal emotion, dies at 75
Environment
- Are synthetic diamonds really better for the planet? The answer isn't clear-cut.Are synthetic diamonds really better for the planet? The answer isn't clear-cut.
- This year's cherry blossom peak bloom was a warning signThis year's cherry blossom peak bloom was a warning sign
- The U.S. just announced an asbestos ban. What took so long?The U.S. just announced an asbestos ban. What took so long?
- The most dangerous job? Inside the world of underwater weldersThe most dangerous job? Inside the world of underwater welders
- The harrowing flight that wild whooping cranes make to surviveThe harrowing flight that wild whooping cranes make to survive
History & Culture
- Why Swedish children celebrate Easter by dressing up as witchesWhy Swedish children celebrate Easter by dressing up as witches
- Meet the powerful yokai that inspired the demon king in ‘Demon Slayer’Meet the powerful yokai that inspired the demon king in ‘Demon Slayer’
- A surprising must-wear for European monarchs? Weasels.A surprising must-wear for European monarchs? Weasels.
- Meet the woman who made Polaroid into a cultural iconMeet the woman who made Polaroid into a cultural icon
Science
- LED light treatments for skin are trendy—but do they actually work?LED light treatments for skin are trendy—but do they actually work?
- NASA smashed an asteroid. The debris could hit Mars.NASA smashed an asteroid. The debris could hit Mars.
- Humans really can have superpowers—scientists are studying themHumans really can have superpowers—scientists are studying them
- Why engineers are concerned about aging infrastructureWhy engineers are concerned about aging infrastructure
Travel
- Why you should try beach-hopping by boat around Paxos, GreeceWhy you should try beach-hopping by boat around Paxos, Greece
- Mansion museums show visitors the gritty side of the Gilded AgeMansion museums show visitors the gritty side of the Gilded Age
- 2024 will be huge for astrotourism—here’s how to plan your trip2024 will be huge for astrotourism—here’s how to plan your trip