And that coupled with social beliefs gets people really entrenched in their thinking. Everyone has bias, but lots of people firmly believe stuff that's demonstrably false. I just try to watch out for that tendency in myself.

I know intelligent people who are theists....go figure.

Everyone has biases. It’s part of being alive and confident enough to make a judgement. Cultural, personal and educationally orientated lenses will help determine one’s viewpoint.

It’s got nothing to do with ‘smart’ or ‘not smart’, it’s about being human.

Very enjoyable read. Smart people maybe only smart in a narrow area and the ability to broaden one's thinking may not even enter their minds unless a problem crops up that can not be rationalized away. Otherwise there is no harm or repercussion from believing in ghosts, fairies or astrology.
Inner reflection at the end of the day helps. Especially if there was a dust up or you had a very stimulating conversation. I tend to wonder how I was perceived, thought of or did I make my point without being over bearing.
I have often wished there was someone who could pick me apart the way we sometimes pick others apart. We can usually see the 'faults' in others and not our selves. It helps to listen to ones self sometimes.