We humans are not as in control of our facilities as we might like to think we are — a lot of who we are and what we do is a byproduct of the chemistry in our brains. Mess that chemistry up, and you can sometimes get very bad results.
A recent scientific study published in the journal Neuropsychologia is an example of that — according to the study, which looked at 150 Vietnam War vets, injuries to the brain boosted religious fundamentalism while reducing the mental flexibility, or the ability to examine our beliefs in a different light.
The damage is specific to a region of the prefrontal cortex called the ventromedial prefrontal cortex, a part of the brain that’s responsible for processing risk evaluation, fear, and plays a role in the inhibition of emotional responses and decision making. You can probably see where this is going, especially given that so much of religious fundamentalism is grounded in fear — but it’s also worth noting that damage to the same region inhibits your ability to read the harmful intentions of others, which could explain why these people keep getting suckered by the carnival barkers in the Republican Party.
Now, the usual caveats apply here: this was a small study, and as the study’s author, Jordan Grafman, noted, the “devil is in the details.” It also doesn’t mean that everyone with this type of brain damage will get suckered by fundamentalism — humans, after all, are incredibly complex creatures and there are a myriad of factors that contribute to our behavior.
However, given the prevalence of abuse and violence in evangelical and fundamentalist homes — even spanking has the potential to do long-term psychological harm, but what happens in their homes is often times so much worse — I’d hazard a non-zero chance more than a few fundamentalists suffer from this type of brain damage, contributing to their religious extremism and our decay as a nation.