Why Evidence is Not Enough

Generally, people rated authors as experts when the views coincided with their own. Kahan and his team created three authors and their books. All three had the same high level of academic standing. (Doctorates from major schools.) In every case, two different, opposing views were written for each author and randomly shown to subjects. The topics were gun control, nuclear power plants, and global warming.

Originally published by the Yale Law School as "Research Paper #205: Cultural Cognition of Scientific Consensus by Dan M. Kahan, Hank Jenkins-Smith and Donald Braman." The paper can be downloaded from the site of our comrades at Mother Jones who offer it here.

This is really just another arithmetic validation of what we know as the "confirmation bias" and the "attribution fallacy." Richard Feynman warned young scientists about the need for ruthless honesty in his famous speech on "Cargo Cult Science." (Available from the CalTech Engineering and Science Library here.)

In short, we tend to agree with and thereby validate experts who agree with us. When presented with facts opposed to our commitments, we denigrate the status of the provider. This ties in with another theme: The Big Sort by Bill Bishop. Over the past generation, Americans have come to socialize only with those who agree with them politically. In the 1960 Presidential election, Kennedy won over Nixon by about 1 vote per precinct, and largely, it was just that: a nation mostly divided narrowly near the middle. Now, precincts tend to be overwhelmingly Republican or Democrat.

It is not just gerrymandering (though there is that), but the fact that people choose to live among those whose political values already mirror their own. The research data show that this correlation is strongest among those with more education. The guys on the bowling team might disagree and still hang out; their bosses on the golf links do not.

Today, perhaps more than a third of working American adults hold bachelor degrees, with the master's being the new bachelor's. University education apparently failed to achieve the lofty goals of Karl Popper and Mark Van Doren two generations ago for a society open to ideas, whose participants benefited from a liberal education embracing literature, mathematics, science, and fine arts.

The blog OrgTheory is written by sociologists of economics, Brayden King, Fabio Rojas, and others. On April 11, 2011, Brayden King posted "When Evidence Isn't Convincing." It summarized research by Daniel Kahan and his colleagues.  Reading that and following the links to the original paper, I posted an earlier version of this blog article to the Objectivist site, Rebirth of Reason.

ALSO ON NECESSARY FACTS
Republican Rebels
Workers Paradise Promised an End to Money
Unlimited Constitutional Government
That Goddam Ayn Rand Book