

A reconstructed Neanderthal skeleton, right, and a modern human version of a skeleton, left, on display at the Museum of Natural History in New York. (AP Photo/Frank Franklin II)

Conservatives often face a lot of questions -- and controversies -- for their views on science. Most notably, only 22 percent of conservative Republicans accept the scientific consensus that global warming is mostly caused by humans. Meanwhile, conservative officials in some states have pushed to undermine the teaching of evolution in public school classrooms.

Liberals get a lot less flack, in general, for ignoring scientific findings. Yet there is also reason to think they, too, are susceptible to allowing their political biases influence their reading of certain scientific questions. And now, a new study just out in the journal Sociological Spectrum accuses them of just that.

The study is far from the authoritative word on the subject of left wing science denial. Rather, it is a provocative, narrow look at the question. In particular, the study examined a group of left wing people -- academic sociologists -- and evaluated their views on a fairly esoteric scientific topic. The specific issue was whether the evolutionary history of human beings has an important influence on our present day behavior. In other words, whether or not we are "blank slates," wholly shaped by the culture around us.

While there's virtually no argument in the scientific community that personality traits like being extroverted run in families and have at least some genetic component, there's been much greater debate among academics about whether other phenomena, such as an inclination toward committing violence and demonstrating an unusual level of jealousy, are rooted in nature rather than life experience.

The new study, by University of Texas-Brownville sociologist Mark Horowitz and two colleagues, surveyed 155 academic sociologists. 56.7 percent of the sample was liberal, another 28.6 percent was identified as radical, and only 4.8 percent were conservative. Horowitz, who describes himself as a politically radical, social-justice oriented researcher, said he wanted to probe their views of the possible evolutionary underpinnings of various human behaviors. "I wanted to get at the really ideological blank slate view, it’s sort of a preemptive assumption that everything is taught, everything is learned," he explained.

Sure enough, the study found that these liberal academics showed a pretty high level of resistance to evolutionary explanations for phenomena ranging from sexual jealousy to male promiscuity.

In fairness, the sociologists were willing to credit some evolutionary-style explanations. Eight-one percent found it either plausible or highly plausible that "some people are born genetically with more intellectual potential than others," and 70 percent ascribed sexual orientation to "biological roots." Meanwhile, nearly 60 percent of sociologists in the sample considered it "plausible" that human beings have a "hardwired" taste preference for foods that are full of fat and sugar, and just under 50 percent thought it plausible that we have an innate fear of snakes and spiders (for very sound, survival-focused reasons).

Yet the study also found that these scholars were less willing to consider evolutionary explanations for other aspects of human behavior, especially those relating to male-female differences. Less than 50 percent considered it plausible that that "feelings of sexual jealousy have a significant evolutionary biological component," for instance, and just 36.4 percent considered it plausible that men "have a greater tendency towards promiscuity than women due to an evolved reproductive strategy.” While it is hard to be absolutely definitive on either of these issues (we weren't there to observe evolution happen), evolutionary psychologists have certainly argued in published studies that people exhibit jealousy in sexual relationships in order to ensure reproductive fidelity and preserve the resources that come from a partner, and that men are more promiscuous because they are not constrained in how often they can attempt to reproduce.

So is this proof positive that academic sociologists are science deniers? Not at all. Still, it's certainly noteworthy that a substantial minority of these scholars are resistant even to the least controversial evolutionary explanations, such as those involving hardwired tastes for certain foods or innate fears of poisonous critters.

But there's also a notable limitation to the study. When it comes to some of the more controversial statements about the evolutionary basis of various human behaviors that were used (for instance, the assertion that "The widely observed tendency for men to try and control women's bodies as property...has a significant evolutionary biological component"), the research doesn't really take a strong stand on whether they're actually true -- which makes it rather hard to call the sociologists woefully biased. Instead, study subjects were merely asked to state whether they considered such statements "highly plausible," "plausible," "implausible," or "highly implausible."

"I think the 'science denial' here among sociologists is their mechanical dismissal of evolutionary reasoning applied to human behaviors -- a dismissal that's much sharper when considering potential sex differences in behavior," says Horowitz, explaining why the study took this approach.

Take one case where sociologists were pretty dismissive -- the assertion that "Feelings of sexual jealousy have a significant evolutionary biological component," which only 44 percent of them considered plausible. Certainly evolutionary psychologists have argued that sexual jealousy is a deeply rooted part of human "nature." One such scholar is David Buss at the University of Texas-Austin, who argues in his book The Dangerous Passion that jealousy is an "adaptation...an evolved solution to a recurrent problem of survival or reproduction," namely, keeping your mate faithful to you.

"Though we can't strictly speaking 'prove' that jealousy was adaptive, we find the mechanical dismissal of the adaptiveness hypothesis dogmatic," comments Horowitz.

There's no doubt that many left leaning academics have historically been quite skeptical about evolutionary psychology, presumably out of the fear that ascribing certain traits to biology suggests that they cannot be changed -- and thus, can perpetuate inequality. The famed Harvard cognitive scientist Steven Pinker extensively challenged their "blank slate" view in a bestselling 2002 book. Going back further, in the storied "sociobiology" wars of the 1970s, evolutionary thinkers like Harvard's E.O. Wilson sought to apply their understanding of humankind's origins to modern human behavior -- and fell into a ferocious row with broadly left-leaning scholars who attacked biological or genetic "determinism," and defended the idea that social factors explain most of what we need to know about why people do what they do.

Asked to comment on Horowitz's study, Pinker had this to say:

I’m not surprised by the findings of the study. Sociology itself is a divided discipline, with radically diverging views on the role of science in general and of course evolution and genetics in particular. Nor am I surprised that gender is the bloodiest shirt. Together with race, gender has always been the biggest impetus for believing in the blank slate, and since the Larry Summers affair almost a decade ago, that has only intensified. (Pinker defended Summers here.)

The prominent New York University social psychologist Jonathan Haidt, author of the bestselling book The Righteous Mind: Why Good People Are Divided Over Politics and Religion and known for criticizing his fellow scholars for their liberal biases, had a similar take:

When the facts conflict with...sacred values, almost everyone finds a way to stick with their values and reject the evidence. On the left, including the academic left, the most sacred issues involve race and gender. So that's where you find the most direct and I'd say flagrant denial of evidence. I think the results of this study do clearly show that political concerns influence the willingness of sociologists to consider a major class of causal factors in human behavior.

None of this is to say that a few sociologists' views about evolution can be considered proportionate with global warming denial, in either the volume of those holding the belief or the belief's consequences. But it does suggest that 100 percent objectivity doesn't exist on any side of the aisle.