Carnegie Mellon University

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August 22, 2017

Polarization Over Controversial Scientific Issues Increases With Education

By Shilo Rea

Shilo Rea
  • Dietrich College of Humanities and Social Sciences
  • 412-268-9064

Carnegie Mellon University researchers have found that people's beliefs about scientific topics that are associated with their political or religious identities become increasingly polarized with education as measured by years in school, science classes and science literacy.

"A lot of science is generally accepted and trusted, but certain topics have become deeply polarizing. We wanted to find out what factors are related to this polarization, and it turns out the 'deficit model' — which says the divisions are due to a lack of education or understanding — does not tell the whole story," said lead author Caitlin Drummond, who recently received her Ph.D. in behavioral decision research from CMU's Department of Social and Decision Sciences. Drummond will be a postdoctoral research fellow at the Erb Institute at the University of Michigan this fall.

Published in the Proceedings of the National Academies of Sciences (PNAS), Drummond and CMU's Baruch Fischhoff used data from the nationally representative General Social Survey. They examined predictors of Americans' beliefs about six potentially controversial issues — stem cell research, the big bang, human evolution, genetically modified foods, nanotechnology and climate change. They measured education by the highest degree earned, science classes taken in high school and college and aptitude on general science facts.

They found that beliefs were correlated with political and religious identity for stem cell research, the big bang and evolution, and with political identity alone on climate change. On each issue, individuals with more education, science education and science literacy had more polarized beliefs.

The researchers found little evidence of political or religious polarization for nanotechnology and genetically modified food.

"These are troubling correlations. We can only speculate about the underlying causes," said Fischhoff, the Howard Heinz University Professor in the Institute for Politics and Strategy and Department of Engineering and Public Policy. "One possibility is that people with more education are more likely to know what they are supposed to say, on these polarized issues, in order to express their identity. Another possibility is that they have more confidence in their ability to argue their case."

The results also showed that for all six issues, people who trust science more are more likely to accept scientific findings.

"We would love to be able to understand what is causing the relationship we observe between education and polarization, and how certain science topics got so polarized in the first place," Drummond said, "disagreements about science seem to be about more than the science itself, but also what the science's implications are for a person's identity."

The research was supported by grants from the National Science Foundation Graduate Research Fellowship, National Science Foundation and Riksbankens Jubileumsfond.