What is the role of chance in human life? If a book tops the bestseller list, if a new product takes over the market, or if people suddenly want to stem immigration, might it all be some kind of accident?
Over a decade ago, a celebrated paper by sociologists Matthew Salganik, Peter Dodds and Duncan Watts tried to answer such questions. They asked: When a song turns out to be a spectacular success, is it because it’s really great, or is it just because the right number of people, at an early stage, were seen to like it?
Salganik and his colleagues created a control group in which people could hear and download one or more of dozens of songs by new bands. In the control group, people were not told anything about what anyone else had downloaded or liked. They were left to make their own independent judgments.
The researchers also created eight other groups, in which people could see how many people had previously downloaded songs in their particular groups. Here was the central question: Would it make a big difference, in terms of ultimate numbers of downloads, if people could see the behavior of others?
It certainly did. While the worst songs (as established by the control group) never ended up at the very top, and while the best songs never ended up at the very bottom, essentially anything else could happen. If a song benefited from a burst of early downloads, it could do really well. If it did not get that benefit, almost any song could be a failure. In short, the judgments of a few early movers could initiate a social cascade, making or breaking a song.
Published in 2006, these findings were electrifying. They suggested that success in business and politics is difficult or even impossible to predict in situations in which nobody can know whether a song, a film, a book, a politician, a cause or an idea will happen to get the social equivalent of visible early downloads.
In subsequent work, Watts has argued that we are often wrong to attribute success or failure to intrinsic merit or to deep cultural forces. Whether it’s the election of President Donald Trump, the views of the Republican Party on immigration or the fame of the Mona Lisa, the real reason might be: Visible downloads, at just the right time.
A new study provides Watts with a lot of support.
Building directly on the music downloads experiment, the sociologist Michael Macy of Cornell University and his collaborators asked whether the visible views of other people could suddenly make identifiable political positions popular among Democrats and unpopular among Republicans — or vice versa.
Here’s how the experiment worked. All participants (consisting of thousands of people) were initially asked whether they identified with Republicans or Democrats. They were then divided into 10 groups. In two of them, participants were asked what they thought about 20 separate issues — without seeing the views of either political party on those issues. This was the “independence condition.” In the eight other groups, participants could see whether Republicans or Democrats were more likely to agree with a position. This was the “influence condition.”
In the influence condition, each participant was asked his own view, which was used to update the relative level of support of each party. That updated level was displayed, in turn, to the next participant in the same group.
The authors carefully selected issues on which people would not be likely to begin with strong convictions along party lines. For example: “Companies should be taxed in the countries where they are headquartered rather than in the countries where their revenues are generated.” And, “The exchange of cryptocurrencies (such as Bitcoin, Ethereum, or Litecoin) should be banned in the United States.” Or this: “Artificial intelligence software should be used to detect online blackmailing on email systems.”
The authors hypothesized that in the influence condition, it would be especially hard to predict where Republicans and Democrats would end up. If the early Republican participants in one group ended up endorsing a position, other Republicans would be more likely to endorse it as well — and Democrats would be more likely to reject it. But if the early Republicans rejected it, other Republicans would reject it as well — and Democrats would endorse it.
That’s exactly what happened.
Across groups, Democrats and Republicans often flipped positions, depending on what the early voters did. On most of the 20 issues, Democrats supported a position in at least one group but rejected it in at least one other, and the same was true of Republicans. As the researchers put it, “Chance variation in a small number of early movers” can have major effects in tipping large populations — and in getting both Republicans and Democrats to embrace a cluster of views that actually have nothing to do with each other.
These findings help explain how members of both parties flip over short periods of time, and also how issues suddenly, and surprisingly, become polarizing across political lines. Immigration is the most obvious example, and note too that as recently as 2007, climate change was not particularly divisive, certainly as compared to 2019.
The more fundamental point is that that the most intense political or cultural divisions may have nothing to do at all with ideology or core values. Everything may depend on the unpredictable outcome of social cascades — driven by the fact that some prominent Republicans, or some prominent Democrats, happened to take a particular position at just the right time.
Cass R. Sunstein is a Bloomberg Opinion columnist. He is the author of “The Cost-Benefit Revolution” and a co-author of “Nudge: Improving Decisions About Health, Wealth and Happiness.”