I posted a web comic poking fun at the irrational fear of the ocean. My carefulness last weekend maybe kept me from getting stung by jellyfish and definitely from stepping on a stingray or skate. There were no sharks that I saw. But then, “absence of evidence is not evidence of absence.”
After some comments, I eventually deleted the post because I was tired of the arguing whether fear is rational or irrational. (It is both which is why I thought the comic funny and posted it, but obviously this was not the correct audience.) I keep to myself more these days to keep from arguing about politics. There has been a temptation to leave Facebook altogether in order to get away from the madness. Something I will not tolerate is that kind of thing on my own posts. I tell people to stop and if anyone eggs it on, then I delete the post.
According to Mercier and Sperber reasoning was not designed to pursue the truth. Reasoning was designed by evolution to help us win arguments. That’s why they call it The Argumentative Theory of Reasoning. 
My own Confirmation Bias screams that this absolutely must be the most true thing I have read this decade. Several posts on this blog demonstrate my fascination with people trusting their ideology over the facts. But this makes sense in an environment where people are mainly looking to prove themselves correct. Someone can be completely reasonable, but if the other has made up their mind there is no changing it. The flow of information only serves to eventually serve up something that supports their view which they will seize upon.
As Behavioral Economics fanboy, I very much am all about humans are not extremely imperfect reasoners. To label anyone, even Neil deGrasse Tyson, as very rational strikes me as irrational. It will be difficult to refrain from not using reasonable as pejorative to mean someone who has stopped thinking beyond only supporting their own view.
From Argumentative Theory of Reasoning published July 16, 2016 at 10:21AM.