Does Social Psychology need more political diversity? Here’s one thing on which everyone can agree: social psychology is overwhelmingly composed of liberals (around 85%). The question of why this is the case, and whether it presents a problem for the field, is more controversial. The topic has exploded out of our conference halls and into major news outlets over the past several years, with claims of both overt hostility and subtle bias against conservative students, colleagues, and their publications, being met with reactions ranging from knee-jerk dismissal to sincere self-reflection and measured methodological critique.

A recent paper led by Jose Duarte of Arizona State University attempts to organize the existing empirical research relevant to this debate. There are two central questions here. First, is the ideological imbalance the result of some kind of bias against conservatives, or some more benign cause, like self-selection into the field? And second, independent of the cause, would more political diversity actually improve the validity of our science?

Duarte et al provide evidence suggesting that social psychology is not a welcoming environment for conservatives. Papers are reviewed differently depending on whether they are considered to support liberal vs. conservative positions, and anonymous surveys reveal a considerable percentage of social psychologists willing to explicitly report negative attitudes towards conservatives. This shouldn’t surprise us. Everything social psychologists know about group behavior tells us that overwhelming homogeneity, especially when defined through an important component of one’s identity like political ideology, will lead to negativity towards an outgroup. We also know a thing or two about confirmation bias and all the ways in which it can affect our decision-making, and it is odd to suggest it might not affect our own. Or to suggest that it might in some domains but not the political.

What about the consequences of this imbalance? Would more political diversity increase the validity of social psychological findings? First, as the authors note, this concern about diversity only applies to the small subset of research dealing with politically charged issues (e.g. gender, race, morality). They argue that having a range of political opinions in these domains would combat the pernicious effects of confirmation bias and groupthink by introducing more dissent. The authors identify several examples of research which they believe to be “tainted” by ideological motivation, and based on their assessment of the state of the research in politically controversial areas, conclude that “the parameters [of the field] are not set properly for the optimum discovery of truth. More political diversity would help the system discover more truth.” Conservative social psychologists would test different hypotheses, better identify methodologies in which liberal values are embedded, and be more critical in general of theories and data that advance liberal narratives.

Finally, the authors offer several recommendations for how to curb any negative effects that political homogeneity poses for scientific validity. First, promote political diversity at the organizational level by changing how diversity is defined in the mission statements of our professional societies. Second, professors should be more mindful of how they treat non-liberal views and actively encourage non-liberals to join the field. Finally, change research practices in ways that allow researchers to better detect where bias might be intruding on decision-making.

These arguments have provoked a range of responses in the field. And here comes one more.

Clearly we should care about any evidence of bias influencing how we conduct or evaluate research. And if we deny even the possibility of such a bias, without reference to empirical investigation, then we will have failed as responsible scientists committed to the pursuit of truth. And ironically so, given that another of the most important lessons from social psychology teaches that we are in no position to evaluate the objectivity of our own decision-making. The data on the hostility of social psychologists towards non-liberals should disturb us at a personal level, too. And if nothing else, motivate change for the mere sake of not being jerks to those with whom we disagree.

But what is the best solution if such a bias does in fact threaten the validity of the field? Let’s grant to the authors that it does exist, it is widespread, and it is threatening scientific validity in a meaningful way. Their solution is straightforward: add more conservatives into the mix. Why? Because this will “diversify the field to the point where individual viewpoint biases begin to cancel each other out.” In short, we need to add the opposite kind of ideological bias to our literature. If liberals distort science one way, conservatives will distort it the opposite way, and it will all cancel out in the end.

This may seem counterintuitive - to have a more reliable and valid science, we need more bias, just a different kind. But it’s rooted in a simple statistical principle. Let’s say we’re collecting guesses of how many M&M’s there are in a large glass jar (there are actually 5,000). If we just ask a population notorious for having a bias towards under-estimating, the average of their guesses will likely be lower than the truth (4,000). And if we just ask a population notorious for having a bias towards over-estimating, the average of their guesses will likely be higher than the truth (6,000). But if we combine these populations and ask for guesses, then the average of the total guesses will be closer to the truth. This is the wisdom of the crowds. Once the errors that individual estimators in the population make become more random, and less systematically biased in one direction, then the average of these guesses will start to converge on the truth.

But how neatly does this principle apply to the issue at hand? What does it mean, in practice, to have the biases that are embedded in researchers’ hypotheses, methods, and peer–reviews “cancel out” over time? If I embed liberal values in my research and Joe Researcher embeds conservatives ones, why is it clear that the ultimate outcome will be more truth discovered as opposed to just more time and resources wasted, both our own as well as the time and resources of others who might be influenced by our ideologically distorted work? Furthermore, if the field adds more ideological diversity it’s unclear whether this would reduce or foment the strength of group bias and polarization.

These questions are as yet unanswered, but they are central to justifying the claim that adding researchers who would “seek to explain the motivations, foibles, and strengths of liberals as well as conservatives” is the best way “for social psychology to correct longstanding errors on politicized topics.” Correcting longstanding errors by adding different errors is a tough sell.

I prefer a different solution, and one in which this kind of paper and inquiry still plays a critical role. Let’s improve the validity of our science by trying to reduce error, not introducing new kinds. The authors dismiss this as an impossibility, claiming that nobody has been able to find effective interventions for reducing confirmation bias. As an ideologically homogeneous group we are bound to repeat our mistakes. But while no silver bullet exists, researchers have indeed identified beneficial interventions to combat bias in decision-making and papers like these can be seen as a strong reminder that social psychology should make this work a priority.

An important component of this pursuit “is an awareness of one’s fallibilities and a sense of humility concerning the limits of one’s knowledge.” Duarte et al have provided evidence of one way in which our professional decisions might systematically deviate from an appropriate application of the scientific method. Let’s be open to this possibility, and take some of the recommendations made here as a way of addressing this concern. Once we have done so, we will have fulfilled our responsibility as scientists. And if more conservatives, or libertarians, or greens, or independents, or whigs, or Californians, or art history majors, or single parents, or whomever are more attracted to the field as a result, then fine. We do not need more ideology in social psychology, we need less. That is the best way to discover more truth.