Paul Nurse, the boss of the Royal Society, recently compared climate skeptics to the people who reject modern medicine, or those who doubt the relationship between HIV and AIDS, and who prefer alternative medicine instead.
I have always thought that this analogy is mostly upside down. Modern medicine is primarily rejected by the people who don't really like or trust applied science and technology, i.e. those who are Luddites who love to romanticize the "life in Nature" that existed before people began to develop their civilization. Those folks are inevitably close to the environmental and other left-wing sentiments.
A particularly explicit example of the distrust in modern medicine is the belief that vaccination causes autism - a claim based on some silly study involving 12 people and a claim that doesn't seem to offer any sensible mechanism to explain the causation. Some pundits superficially suggest that it's the right-wing nutjobs and conservative Christians who believe such things. However, it turns out that it's mostly the liberals, parents who want to educate politically correct children.
There are two main reasons why they're mostly liberals: one of them is the distrust in the modern technology, as described in the previous paragraph. Another one is the left-wing belief that key characteristics of human beings - such as their autistic character or intelligence - are results of the social pressures and various events in their lives rather than innate properties.
Bill Zajc has sent me a link to a very realistic interview with Seth Mnookin (the author of a new book linked on the left) in the Science Magazine:
Just to be sure: I have always hated vaccination and when I was a small schoolkid, I liked to faint a little bit after the act. ;-) Still, I have never really believed it was harmful.
Via Bill Zajc