Writing in Dædalus (Fall 2004), Jonathan Haidt and Craig Joseph state that while political conservatives value the virtues of kindness, respect for authority, fairness, and spiritual purity, traits they interestingly share with American Muslims, liberals have a much keener ability to detect victimization and care more about suffering and compassion and the virtues of equality, equal rights, and fairness.  "For liberals, the conservative virtues of hierarchy and order" (respect for authority) "seem too closely related to oppression, and the conservative virtues of purity seem to have too often been used to exclude or morally taint whole groups (e.g., blacks, homosexuals, sexually active women)."

On divisive issues such as gay marriage, cloning, and stem-cell research, Haidt and Joseph observe that liberals focus on promoting individual welfare and individual rights. "Conservatives understand these arguments, but they have a more multivocal moral life, drawing on a wider set of moral intuitions.  They also have to integrate their deeply intuitive aversion to ‘playing God’ and their more finely honed and valued sense of disgust." 

Leon Kass, President Bush’s bioethics advisor, based his critique of human cloning in part on the fact that it offends and repulses many people. While granting that disgust is not by itself an argument, he suggests that there is a form of wisdom in repugnance. “Shallow are the souls that have forgotten how to shudder,” he wrote.

Based on this, I observe that both sides, conservative and liberal, appear to each other as "unintelligent" or "dumb" not due to differences in education or knowledge, but based on behaviors by the others that do not appear to conform with their own deeply based values, beliefs that each side may not even realize they hold. To liberals, it seems "dumb" to resist scientific research that might someday relieve the suffering of many, but conservatives object to the research not based on its possible outcome, but on their intuitive sense of repulsion.  To conservatives, it seems "dumb" to champion the cause of an underdog class at the possible expense of one's own status, but liberals don't value loyalty to one's own peer group as much as conservatives and may not perceive in justice a trade-off between two separate tribes.

They're not stupid and we're not smart - we're all just different and are looking at life through different colored glasses.