My sister is no fool; she's a hard-working and clever medical student. My uncle is undeniably intelligent; we've had interesting and informed discussions on any number of topics. But they share one trait that drives me batty: Neither of them is really willing to accept that human activity is causing climate change.
Neither of them is Republican. (Because ... we're all British.) Neither of them has any logical reason that I can see to dislike the topic. My sister apparently avoids it because it makes her uncomfortable; my uncle is willing to accept that the climate changes, but thinks that such changes derive from natural causes and that human activity could not cause a shift.
As someone who believes that anthropogenic climate change is one of the greatest threats that we as a species will ever face, along with it being the death knell for countless other strange and wonderful species, this tendancy of theirs drives me up the wall. I love them both. But they drive me crazy.