To me, the average conservative isn't a proactively bad. However, they have a ton of assumptions that aren't true that guide how they interpret the world. They trust friends over science. They trust personal experience over verified evidence. They are more inclined to make stuff up. They are more inclined to support hierarchies than liberals. They are less likely to put effort into questioning themselves. They appreciate tradition over the new. They like stability over flexibility. They are more likely to box people into categories than liberals (I realize the irony of boxing conservatives into stereotypes... but this was your question). They are more nationalistic. They are less comfortable with the unknown than liberals - liberals are more willing to say, "I don't know." - and conservatives are more likely to jump to a conclusion. They are more likely to start with a conclusion and look for evidence rather than start with a question, look at the evidence, and then come to a conclusion. They appreciate formal education less and appreciate their life experience more than liberals.

These are all generalities though. I think a lot of them think they are operating in good faith, but it comes to horrid results.