Last week, we went through a familiar ritual: Hand-wringing and alarm over Republican politicians denying scientific reality. This time around, the main focus was Rick Santorum, the anti-evolutionist and climate change denier who is one of the worst of the worst in this area (and who promptly obliged by making a new and fresh anti-science statement).

But hey, it's always something.

We've been repeating this pattern at least since the early George W. Bush years. A Republican makes a dubious scientific claim, a Republican officeholder or appointee suppresses a scientific report, a scientist in a Republican administration gets muzzled...the names change, but the story does not. I chronicled it all in a book that is now seven years old--The Republican War on Science--and I wasn't the first.

Nor will I be the last. The very fact that Jon Huntsman (who just nabbed third place in New Hampshire) has been able to successfully frame himself as the "pro-science" Republican candidate itself speaks to the misalignment of his competitors with reality.

Some of the conservative denial of science may well be cynical in nature. But there's no doubt from polls that large numbers of conservatives really believe this stuff--that global warming isn't real, nor is evolution. And indeed, the denial of reality extends well beyond science and into other fields like economics and history.

When you have a phenomenon this recurrent, it seems to me that at some point, it is reasonable to stop and ponder deeper causes. And are there any?

Recently, I posted a list of seven recent scientific studies showing that liberals and conservatives differ in ways that go far beyond their philosophies or views on politics. We're talking about things like physiological responses when shown different kinds of words or images, and performance in neuroscience tests. Take just one recent example: Conservatives show stronger responses to negative and threatening stimuli (words like "vomit" and "disgust"). Could this also prompt more knee jerk reactions to scientific information that is perceived as threatening (or words like "evolution")?

The point is not necessarily that the answer is yes, but rather that it is reasonable to ask questions like these. The root causes of our political differences are now under intensive exploration by multiple different research groups, which are churning out quite a lot of published, peer reviewed science. And while this work is surely not complete (science never is), it is also unlikely to be just plain wrong. Indeed, after having spent the past year reading this research and interviewing the scientists producing it, I can confidently say that those seven studies are just the tip of the iceberg.

Here's the bottom line: An increasing body of science suggests that we disagree about politics not for intellectual or philosophical reasons, but because we have fundamentally different ways of responding to the basic information presented to us by the world. These are often ways of which we are not even aware--automatic, subconscious--but that color all of our perceptions, and that effectively drive us apart politically.

What's more, what is true for how we come to our opinions about politics is also, assuredly, true for how we approach "facts" that are perceived to have some bearing on the validity of our political opinions--whether those facts are scientific, economic, historical or even theological in nature.

Thus far--and not surprisingly--conservatives don't seem so fond of the emerging science of our politics. They seem to consider it demeaning--yet another slight aimed at them by "liberal" academia.

And it's partly true: the research in question is--like all scholarly work--largely conducted by scientists and academic liberals who want to achieve a better understanding of the nature of our political dysfunction, and also of why we are divided over things like scientific reality. But ironically, when considered in all of its complexity and nuance, much of the research actually makes Republicans look very good (decisive, resolute, loyal) relative to liberals or Democrats--and certainly a lot more politically effective.

Frankly, it seems to me that this approach ought to prompt more tolerance and understanding across our political divides, rather than less. After all, if we are reaching many of our political and even our factual opinions for reasons that we're not even conscious of--if we're effectively being pushed to accept some views rather than others, because they resonate at a deep psychological level and just "feel right"--then the only appropriate response, it seems to me, is a deeply liberal one: Tolerance. Understanding. Acceptance. Empathy.

In other words, the next time a Republican denies global warming, liberals ought to be better able to check the impulse to say "what an idiot!" and instead say something like, "I can understand why they have that kind of a response."

But then again, the next time a liberal or Democrat does something typically and predictably liberal, Republicans ought to do the same. And now the paradox: What if liberals are more open to (and simply curious about) the science of liberals than conservatives are regarding the science of conservatives?

If so, then we'll still probably have a factually polarized political arena--but at least we'll know a little bit more about why.