How reliable is academic research? Not very, it seems, after noting that the Journal of Vibration and Control, a reputable academic publication, had to retract 60 different papers over the summer.

The editors concluded that Chen-Yuan Chen, a researcher in Taiwan, had created a “peer-review and citation ring.”

OK, it’s not exactly a “Sopranos” plot. But it’s pretty shady for the world of higher education. Chen went to great lengths to make up fake email addresses and even assume the names of other scientists to write approvingly of his own research.

In a sense, though, he was just exploiting the deep flaws of the peer review system. The academy has become a kind of club where friends give friends flattering assessments of research, which essentially guarantees promotions and tenure.

Here’s how the former editor of the British Medical Journal explained peer review:

“The editor looks at the title of the paper and sends it to two friends whom the editor thinks know something about the subject. If both advise publication the editor sends it to the printers. If both advise against publication the editor rejects the paper. If the reviewers disagree the editor sends it to a third reviewer and does whatever he or she advises. This … is little better than tossing a coin.”

But it’s not just the clubbiness of academia that is to blame. There is such ideological uniformity in the ivory tower that no one ever questions the important assumptions behind anyone else’s research.

A forthcoming article in Behavioral and Brain Sciences, published by Cambridge University Press, describes this problem in detail.

The article, whose lead author is New York University’s Jonathan Haidt, finds that academic psychology has lost nearly all of its political diversity in the last 50 years and that the validity of the discipline has been “undermined” as a result.

If you don’t subscribe to modern environmentalist propaganda, you might as well be Caveman Og, swinging your club at wooly mammoths.

And while the authors note that greater political diversity would improve things, nonliberals face a “hostile climate and discrimination.”

Just how bad is the problem? It’s not just that few academics voted for Mitt Romney. At a recent meeting of the Society for Personality and Social Psychology, Haidt asked the audience by show of hands to identify themselves by their political orientation.

He estimates the resulting ratio of liberals to conservatives at 267:1. If anything, it was probably worse, since many conservatives don’t want to be “outed” to their colleagues.

This ideological one-sidedness, according to Haidt and his co-authors, has consequences far beyond the common bullying of conservative students.

They cite, for instance, a paper about the “denial of environmental realities” by some of their colleagues in the British Journal of Social Psychology.

When subjects exhibit the “denial of the possibility of an ecological crisis” or the “denial of the danger of disrupting balance in nature,” the authors characterize them as tapping into a “primitive” belief system.

In other words, if you don’t subscribe to modern environmentalist propaganda, you might as well be Caveman Og, swinging your club at wooly mammoths. Haidt and his colleagues patiently explain how terms like “balance of nature” and “crisis” are vague.

Since they are not “facts,” it’s not possible to be “in denial” about them. “Disagreement,” they write, “is not the same … as denial.” Such concepts are skipped over in grad school, apparently.

Another paper in the Journal of Personality and Social Psychology found that people “high in right-wing authoritarianism were more likely to go along with the unethical decisions of leaders.”

Forget about defining right-wing authoritarianism. What constitutes “unethical behavior”?

“Not formally taking a female colleague’s side in her sexual harassment complaint against her subordinate (given little information about the case) and a worker placing the well-being of his or her company above unspecified harms to the environment.”

Obviously, if you engage in such behavior, you’re simply a bad person.

Christian Smith, a professor of sociology at Notre Dame, has spent a career trying to combat the groupthink of academia. In his new book, “The Sacred Project of American Sociology,” Smith offers a scathing indictment of his discipline.

In his field of study, the sociology of religion, most professors begin with the assumption that “ordinary people’s naïve experiences of religious faith and sacred practice ought not to be taken seriously on their own terms,” but are better understood through the concepts of “status struggles, coping mechanisms, gender inequalities, class interests, social control, etc.”

In other words, religion is the opiate of the masses. End of argument.

If that’s where you start, it’s pretty clear where you’re going to end up. The only way to combat the production of academic research that simply confirms what liberal academics already believe is by having someone there to question these assumptions.

As Smith tells me, “Knowledge is advanced through the clash of rival interpretations of the evidence.”

The professors must have missed that memo.