If it is, they never mentioned it in my biology classes. Then again that was a while ago. I know some people like coffee, some people hate it, some people only like it certain ways. It could be biological. But I like to think there are parts of our personality that aren't connected to any forces besides randomness.

The negative aspects do tend to be the parts that are harder to ignore. And sometimes the opposite of them are still negatives. But every so often there's something that's not terrible.