8 Scientific Reason Why People Are The Worst
5. You'll Argue To Win For The Sake Of It
As humans, we generally pride ourselves on our ability to reason. However, studies find that we use our unique ability, not in the noble pursuit of truth, but as a stick to beat people with in arguments.
Some research has shown that we're actually pretty bad a pure reasoning outside of an argumentative context. Unfortunately, our ability to "reason" means that we're less likely to view things objectively and more able to twist things around to fit with our world view, which explains our propensity for confirmation bias and why your infuriating cousin still thinks that the Illuminati were behind 9/11. This is basically rooted in the human drive to win.
This instinct has been bred into us over the course of our evolution (seeing as the people who win tend to be the ones who pass on their genes). The drive to be at least perceived as right trumps the drive to be actually right and so our ability to reason is used, not to find the truth, but as a tool of rhetoric to convince others that you're right. Evolutionarily speaking, sticking to your guns is a sign of strength and admitting you were wrong is a sign of weakness. Our brains are all about building up a model of the world that works, but this is a very complex process and it uses a lot of cheats and shortcuts to do it. It takes much less energy to prop our world views up on a throne of lies than tear the whole thing down and start again.
So long as our wrongly held views are not going to take us out of the gene pool (i.e. "I think there's a God that lives on the mountain" as opposed to "I could survive a fall from this cliff"), it benefits us to be pigheaded.