Every ideology has its factual holes. The press of ideas and values highlights certain facts and obscures others, and when the ideology grows in force in local settings, those obscured facts disappear entirely, or even turn into outright falsehoods in the eyes of the "ideologues."
George Mason economics professor Daniel Klein and Zogby International researcher Zelija Buturovic have analyzed the findings of a Zogby survey that reveals the dangers of excessive ideological conformity.
Zogby posed to nearly 4,835 American adults eight assertions about basic economics and asked them to agree or disagree. The prompts included "Mandatory licensing of professional services increases the prices of those services," "Overall, the standard of living is higher today than it was 30 years ago," and "Rent control leads to housing shortages."
The survey also broke the respondents down into six ideological groups, "Very conservative," "Libertarian," "Conservative," "Moderate," "Liberal," "Progressive/very liberal." It also asked respondents for their political party affiliation.
Here are the researchers' conclusions as recounted in a Wall Street Journal op-ed by Klein this week: "Americans in the first three categories do reasonably well. But the left has trouble squaring economic thinking with their political psychology, morals and aesthetics." For instance, "On the question about living standards, the portion of progressive/very liberals answering incorrectly (61%) was more than four times that of conservatives (13%) and almost three times that of libertarians (21%)."
Furthermore, "Those responding Democratic averaged 4.59 incorrect answers. Republicans averaged 1.61 incorrect, and Libertarians 1.26 incorrect."
This is to say that possession of certain economic facts varied by ideology. The right performed better, much better. This is not to say that the left would not perform better in other areas. I think it likely that it would. But the survey does support the notion of factual blind spots, and we may infer that in more or less closed bodies such as academic departments in which one ideology reigns, the blind spots can dilate, progressively turning into accepted wisdom. Add to that the complacency that follows and you have a formula for intellectual weakness.