Certain staunch American conservatives and liberals have found something they can agree on. Raw milk. They believe unpasteurized milk is perfectly safe and healthy to drink, and they dismiss any science and scientists who say it is not.

Passionate advocates from both ends of the political spectrum object to state and federal laws regulating the sale of unpasteurized milk. They believe pasteurization deprives cows’ milk of important nutrients that bolster the human immune system and ward off illness.  And they say government has no business telling citizens they can’t sell it or buy it.

Whatever their politics, these raw milk devotees are at odds with the overwhelming weight of scientific and medical authorities, who declare unpasteurized milk is no healthier than processed, and the lack of pasteurization greatly increases the risks of being sickened by E. coli, Campylobacter or other harmful microbes.

This, of course, is only one issue on which significant numbers of Americans are in conflict with science.  While most scientists are convinced that burning oil and coal causes global warming, many conservatives insist that, if climate change is occurring at all, it is part of a natural cycle. Science says homosexuality is largely an inherited trait; critics say it’s a choice. Most scientific research indicates that genetically modified foods are safe for consumption and for the environment, but millions of Americans believe otherwise.

And, of course, nearly 50 percent of Americans, and especially conservative Christians, dismiss evolution theory, a fundamental concept accepted by virtually every scientist on earth.

And so forth.  Americans seem to be fiercely resistant to scientific authority – at least in certain areas that affect their lives.

For this, liberals blame conservative Republicans, who are far more likely than liberals to question climate change or Darwinist evolution. Science writer Chris Mooney has written three books on the subject, including “The Republican War on Science.” As partisanship has deepened in America, Mooney argues, conservatives have increasingly challenged scientific ideas. “Science denial today is considerably more prominent on the political right,” he writes, especially on  “climate and related environmental issues, anti-evolutionism, attacks on reproductive health science by the Christian right and biomedical issues.”

There are a number of reasons for this. The Republican alliance with fundamentalist Christians has lured support in the South and the heartland, but this has required the party to take nonscientific stances on evolution and other divisive issues.

But if Republicans feel no affection for the scientists, then the feeling appears to be mutual.  A 2009 study by the Pew Research Center found that only six percent of U.S. scientists identify themselves as Republicans, compared with 55 percent who see themselves as Democrats and 39 percent who say they are independent. Similarly, 9 percent of scientists said they were “conservative,” while two thirds said they were “liberal” or “very liberal.”

That partisanship, in turn, could be attributed to the fact that most scientists work for government, where Republicans are forever trying to cut their budgets. Perhaps scientists are merely expressing their self interest.

Conservatives, however, hold no monopoly on hostility toward science.  Liberal Democrats who subscribe to the scientific views of evolution and climate change are liable to part ways on such issues as genetically modified foods and the alleged link between childhood vaccines and autism.  Liberal voices ranging from Robert F. Kennedy Jr. to the Huffington Post have challenged the science establishment on the autism theory.

“The assertion that childhood vaccines are driving autism rates has been undermined by multiple epidemiological studies,” writes Mooney.

Some of this skepticism toward science may be built into our national character.  Some 175 years ago, the French writer Alexis de Tocqueville argued that those odd Americans had no use for scientific theory. “They mistrust systems,” he explained. “Scientific precedents have little weight with them… Hardly anyone in the United States devotes himself to the essentially theoretical and abstract portion of human knowledge.”

This is especially true when people are confronted with practical decisions such as raw milk, says Dr. John Kobayashi, a University of Washington professor and widely respected authority on foodborne illness.  “While a mistrust of science exists, much of the problem is the difficulty in making rational risk-benefit decisions,” he says.

There’s simply too much information out there, bouncing around the Internet, readily available, making it difficult for people to do the homework necessary to make thoughtful decisions.

And with all that information, one can always Google up a scientific source that reinforces what we already believe.

Take evolution, for example.  While the vast majority of scientists support Darwin’s theory, there are a few seemingly credible voices who don’t.  And that small minority of voices is enough to provide political and intellectual cover for evolution critics such as Seattle’s Discovery Institute.

These conflicts are nothing new, says Dan Kahan, a Yale Law professor who has studied American attitudes toward risk and science. “There’s so many voices – Fox News and CNN and ABC and MSNBC… Twitter and Facebook. And fifteen books on either side of any issue.  Is anybody actually reading those books?  Who’s actually paying attention?”

In fact, Kahan says, most Americans agree on most scientific issues. The areas of disagreement, whether it is evolution or climate change or raw milk, are actually the exceptions to the rule, he says.

And on those issues, people are merely seeking out information that supports what they already believe, he adds.  It’s fundamental human nature.

“People may look like they are ignoring the evidence. But you inquire more closely, and you find out they actually believe their positions are consistent with science.”

So you have pro-evolution people and anti-evolution people, pro raw milk and anti raw milk people, all scouring the information universe, looking for science to support their opinions … and finding it.