Using Math To Explain Our Polarized Society

Using a new mathematical model, a team of Stanford researchers has gained new insight into why American society seems increasingly polarized.

Based on their mathematical models the team asserts that polarization is less a reflection on the state of society, but more like indicator of the process people go through to form opinions.

The Stanford team, unsatisfied with flaws in previous models that tried to explain societal polarization with the theory known as homophily - that like seeks like - calculated a new model based on something called biased assumption. In biased assumption people more easily accept evidence that supports their own their own opinion and, likewise, tend to discredit evidence that that goes against what they believe. Put another way, biased assumption causes people look at inconclusive evidence in a way that is more favorable to their existing point of view.

"It seems counter-intuitive that two individuals would arrive at a more divergent opinion when presented with identical information that is inconclusive, but that's what happens," said David Lee, a Stanford doctoral candidate in electrical engineering and a co-author of the paper. "You might think that seeing identical evidence would produce greater moderation and agreement, but it doesn't."

In an op-ed in The New York Times, Harvard professor Cass R. Sunstein wrote about a memorable example of the biased assumption phenomenon at work when both liberals and conservatives were given correct and apparently credible evidence showing that the George W. Bush administration was incorrect in asserting that Iraq had an active unconventional weapons program. After receiving the correct information, conservatives became even more likely to believe that Iraq had such weapons and was seeking to develop more, Sunstein said.

What Sunstein pointed out in 2012 echoes what the Stanford team concludes:

The person or organization delivering the information has more to do with how people form their opinions than the information itself.

"We want to use the insight from our mathematical analysis to create recommendation engines and online collaboration tools to help people find common ground on difficult and divisive societal issues," Stanford's Lee said in a press statement. 

The Stanford team demonstrated how this is possible by building an online budget tool that invited people to take on the role of Congress allocating the budget, then letting them compare their budgets with the budgets done by people in Washington, like President Barack Obama and Rep. Paul Ryan.

"What you learn when you see the two budgets side-by-side is just how similar they really are. By articulating the similarities rather than the differences we can focus on collaborating to find a solution," said Ashish Goel, a professor in the Department of Management Science and Engineering and co-author of the paper.