If conservatives seem stupid, at least in comparison to liberals (especially given the way they have been acting this week), it's because they are, and science backs this up.
Citing a study by Satoshi Kanazawa in the March 2010 issue of Social Psychology Quarterly (which is behind a paywall), ScienceDaily states:
More intelligent people are statistically significantly more likely to exhibit social values and religious and political preferences that are novel to the human species in evolutionary history. Specifically, liberalism and atheism, and for men (but not women), preference for sexual exclusivity correlate with higher intelligence, a new study finds.
Central to this concept of higher intelligence is Kanazawa's idea of The Savannah Principle which medical writer Tom Rees, who has a PhD in biotechnology, describes:
The idea behind the Savannah Principle is that we have a range of cognitive biases that adapted us for survival in small groups of hunter gatherers, but which are maladaptive for modern life. The controversial bit is that he goes further than that, claiming that people with high IQ can over-ride their evolutionary heritage
In other words, humankind evolved over tens of thousands of years and adapted specifically to life in East Africa as hunter gatherers. It was the development of general intelligence, the ability to think and reason, that allowed humans to leave East Africa, migrate around the world, and adapt to and thrive in any environment through innovation and novelty. It is that same general intelligence that allows us to thrive in the modern world. ScienceDaily states:
General intelligence, the ability to think and reason, endowed our ancestors with advantages in solving evolutionarily novel problems for which they did not have innate solutions," says Satoshi Kanazawa, an evolutionary psychologist at the London School of Economics and Political Science. "As a result, more intelligent people are more likely to recognize and understand such novel entities and situations than less intelligent people, and some of these entities and situations are preferences, values, and lifestyles.
ScienceDaily explains that evolution has designed us to be conservative, clannish, xenophobic hunter gatherers and it is our higher intelligence that helps us to override that, according to Kanazawa. Is it any wonder then that studies show self-identified liberals to have higher intelligence than conservatives?
Data from the National Longitudinal Study of Adolescent Health (Add Health) support Kanazawa's hypothesis. Young adults who subjectively identify themselves as "very liberal" have an average IQ of 106 during adolescence while those who identify themselves as "very conservative" have an average IQ of 95 during adolescence.
Now this may not seem like a big difference, but blogger and Unz Foundation Junior Fellow and avowed conservative Razib Khan explains the significance of this:
Assume the "very conservative" and "very liberal" categories are normally distributed in intelligence. The mean is 95 and 106. What percentage of people within each category are going to have IQs of 130 and above?
0.92% of "very conservative" individuals
5.48% of "very liberal" individuals
The modest average differences loom larger at the tails. As it happens, the 130 IQ level is around where the elites of our society seem to be drawn. Two standard deviations above the norm (or higher in the case of scientists, management consultants, corporate lawyers, etc.).
This means that it's lonely at the top of the intelligence elite for conservatives.
Khan goes on to speculate that it will be difficult for Mitt Romney to get the nomination in 2012 because he is "too obviously smart" for conservatives. I guess this also explains the appeal of Sarah Palin for conservatives. The key to success is to be "plainly average."
I think this also explains why President Obama is sometimes criticized for acting "professorial." It means that his keen intelligence is showing and that is disconcerting to conservatives.
So maybe this helps explain why so much conservative behavior this week has been so nonsensical. They simply haven't evolved from the Savannah, they're still in hunter gatherer mode. They lack the capacity for novelty and innovation that liberals have. And mostly they lack general intelligence, and there is increasing science to prove it.