I was being an ass, but yeah, I think the well-documented conservative ability to compartmentalize and live in a neat, orderly mental world helps a lot.
More anecdotal than the above example, but something I believe it is true: conservatives are less likely to cross the line from empathy (understanding) to sympathy (feeling bad for) when it comes to the plights of other people. In other words, if Bob the conservative and Mary the liberal on their way to dinner together, and they see a charity billboard with a gut-wrenching picture of a starving child or beaten housewife, their reactions would be very different.
Bob says "Wow, that sucks." and takes a mental note to check out the organization later, to see if they're a worthy charity. Maybe even donate some money. Then, he goes right on to enjoy his meal with a big smile on his face. He comments on the deliciousness of the crabbed-stuffed mushroom appetizer, wondering aloud if the main course could possibly top it...
Mary, on the other hand, has a more visceral reaction, literally
feeling the pain child/battered wife on an emotional level. She picks at her dinner like a bird, almost guiltily, as she feels like she just has to do
something to stop the suffering she saw on that billboard. When Bob suggests looking at the dessert tray, she chastises chastising Bob for being so nonchalant:
how can you think about eating so decadently after seeing something like that?

Bookmarks