Previous research had suggested that the ventromedial prefrontal cortex, which is situated in the frontal lobe of the brain, was a “critical hub” for belief systems.

The new study found damage to the ventromedial prefrontal cortex appeared to cause an increase in religious fundamentalism by reducing cognitive flexibility – meaning the ability to update our beliefs in light of new evidence – along with lowering the personality trait of openness.

The researchers examined 119 veterans with penetrating traumatic brain injury and 30 Vietnam veterans with no history of brain injury.