This BBS target article may be among the most important papers on the practice of psychology in the recent history of the field. Left-wing bias has indeed been a substantial distorter of large swaths of research and theory. How could it not be, given everything we (as psychologists, of all people!) know about the intellectually corrupting effects of ideology, in-group consensus, and the demonizing of dissenters? Duarte et al. brilliantly document and diagnose the problem, though their survey of the damage is only partial. In addition to the topics they call out, I would add the study of sex differences, violence, genetic contributors to economic inequality, cultural contributors to economic inequality, and the shaping of personality and intelligence (see Pinker Reference Pinker2002; Reference Pinker2011a; also see Susan Pinker [Reference Pinker2008]).

The problem extends beyond particular research areas. I suspect that a left-liberal bias also explains the paucity of deep explanations in psychology – the fact that our “theories” often consist of an ever-lengthening list of biases, fallacies, illusions, neglects, blindnesses, and fundamental errors, each of which pretty much restates the finding that human beings are bad at something. To explain why humans are bad at what they are bad at, and good at what they are good at, psychology needs to invoke deeper principles from disciplines that are more foundational than psychology itself, including economics, genetics, and evolutionary biology. But these sources of explanatory depth are often excluded from psychologists' consciousness because of their perceived political baggage (Pinker Reference Pinker2002).

In addition to compromising scientific psychology, the political bias identified by Duarte et al. has corroded trust in science as a whole. To take a baleful example, skeptics of anthropogenic climate change commonly write off the scientific consensus by claiming that the left-wing bias of academic researchers is so pervasive and unacknowledged that nothing coming out of the academy can be taken at face value. They are surely wrong about climate science, but our field has given them ample evidence that such a bias exists. A salient example is the conspicuous outrage and lack of balanced debate after Lawrence Summers' 2005 remarks on the interpretation of evidence regarding gender discrimination in academia (see Pinker Reference Pinker2005).

The social sciences must return to politically disinterested inquiry, and the target article is a welcome call to action. I will add two friendly amendments.

First, I'm not sure that Christian Smith's liberal progress narrative is an entirely accurate summary of the political orientation of social scientists. As someone who has documented that there is a good deal of empirical truth to the narrative itself – we have, in fact, made a great deal of progress since the Enlightenment (Pinker Reference Pinker2011a) – I can vouch that contemporary left-liberals adamantly deny it (though they do believe the struggle for such progress is worth prosecuting). Abolition of slavery? There are more slaves today, I am frequently informed, than at any time in history. The end of racial segregation? American prisons are the new Jim Crow. A decline in racism? It has just gone underground in the form of implicit biases. The rights and safety of women? The barriers have just become better hidden, while women are in more danger than ever, especially the one in four college women who have been raped. The end of barbaric corporal punishment? We now live in a Panopticon-style carceral society whose subtle forms of surveillance and conformity make burning at the stake no longer necessary.

These days it is the libertarians, not the left-liberals, who tend to believe in progress (e.g., Ridley Reference Ridley2010). Rather than liberal progress, the narrative of many left-leaning academics is that society consists of a zero-sum competition among classes, genders, and races, and the mission worth dedicating one's life to achieving is ensuring that the currently disadvantaged groups get their fair share of the power and resources. For these reasons, Duarte et al.'s repeated reference to the “liberal progress narrative” seems to miss the mark. None of the examples of political bias that they call out requires a conviction that our society has made progress.

A second observation: The authors had a stroke of rhetorical genius in using the left-liberal shibboleth of “diversity” against them. And they make an interesting case that some kind of affirmative action for conservatives and libertarians might help neutralize the bias. But the analogy between race and gender, on the one hand, and political ideology, on the other, is partial at best. Gilbert and Sullivan notwithstanding, one is not born a liberal or a conservative in the same way one is born a male or a female, a European or an Asian or an African. Political ideologies are not arbitrary markers but have intellectual content which can be exposed, debated, and, when appropriate, discounted. All scientists should do this, including liberals and leftists; we shouldn't assume that leftists are hardwired to bias their science in a leftward direction, requiring a faction of right-wingers to cancel them out with an opposing bias. It would be a shame if this tactical suggestion of the authors' sparked a diversionary debate over the merits of quotas and reverse discrimination, and overshadowed their larger point that the conduct of good science requires that we all do everything possible to identify and minimize the distortions of parochial ideologies.