It is important to understand the phenomenon of religious fundamentalism from a psychological and neurological perspective because religious beliefs play a massive role in driving and influencing human behavior and politics throughout the world. Through the years, there has been a variety of research studies conducted to investigate the cognitive and neural systems involved in religious fundamentalism. One of them in particular, led by Jordan Grafman of Northwestern University, links brain damage and religious fundamentalism.

“We need to understand how distinct religious beliefs are from moral, legal, political, and economic beliefs in their representations in the brain, the nature of conversion from one belief system to another, the difference between belief and agency, and the nature of the depth of knowledge that individuals use to access and report their beliefs.” – Grafman

People practicing Islam

Raw Story defines religious beliefs to be “thought of as socially transmitted mental representations that consist of supernatural events and entities assumed to be real.” While empirical beliefs are “based on how the world appears to be and are updated as new evidence accumulates or when new theories with better predictive power emerge.”


The difference between the two lies in the fact that religious beliefs are not usually updated in response to new evidence or scientific explanations like empirical beliefs are. Because of this, religious beliefs are strongly associated with conservatism, meaning that they are fixed and rigid. That is why conservatism is therefore used to help promote predictability and coherence to the rules of society among individuals within the group.

Religious fundamentalism is defined as “an ideology that emphasizes traditional religious texts and rituals and discourages progressive thinking about religion and social issues.” Anything that questions or challenges religious fundamentalists beliefs or way of life is generally opposed.

A pro-Osama Bin Laden demonstration outside the US embassy in London in 2011

A pro-Osama Bin Laden demonstration outside the US embassy in London in 2011, Getty Images

That is why there is a greater chance that they will often be aggressive towards anyone who does not share their specific set of supernatural beliefs. They will most likely also reject science. These oppositions are seen as existential threats to their entire worldview.

Grafman’s research utilized data gathered from Vietnam War veterans as part of the Vietnam Head Injury Study. They compared levels of religious fundamentalism between 119 vets who had lesions and 30 veterans who didn’t. Every person took the same set of tests (questionnaires).

We all possess a mental trait called ‘cognitive flexibility’ – the brain’s ability to easily switch from thinking about one concept to another, and to think about multiple things simultaneously. Through evolutionary necessity, we acquired this useful skill. It allows us to update beliefs in light of new evidence. Psychologically speaking, cognitive flexibility is a term that describes a personality trait which involves dimensions like curiosity, creativity, and open-mindedness.

Prefrontal cortex

Cognitive flexibility allows individuals to make more accurate predictions about the world under new and changing conditions and is therefore a crucial mental characteristic for adapting to new environments. This ability is a role of the prefrontal cortex. They discovered that through brain imaging research.

“The variation in the nature of religious beliefs are governed by specific brain areas in the anterior parts of the human brain and those brain areas are among the most recently evolved areas of the human brain.” – Grafman

If there is damage to the prefrontal cortex in an individual then their cognitive flexibility may be impaired. It means that open-mindedness presents a challenge; and since religious fundamentalism involves a strict adherence to a rigid set of beliefs, it would seem like the comfortable option for such an individual.

Westboro Baptist Church

Westboro Baptist Church members

This is why Dr. Grafman and his team predicted that participants with lesions to this region of the brain would score low on measures of cognitive flexibility and trait openness and high on measures of religious fundamentalism – which they did. These results suggest that damage to the vmPFC (prefrontal cortex region specific to cognitive flexibility) indirectly promotes religious fundamentalism by suppressing both cognitive flexibility and openness.

In conclusion, these findings suggest that impaired functioning in the prefrontal cortex—whether from brain trauma, a psychological disorder, a drug or alcohol addiction, or simply a particular genetic profile—can make an individual susceptible to religious fundamentalism. What this means is that in some people, the system of “belief revision” may become suppressed due to brain damage.

This study is just intended to be a contribution to a growing body of knowledge about how religious experiences are formed in the brain. For further information, you can read the study called “Biological and cognitive underpinnings of religious fundamentalism” which was published in the journal Neuropsychologia.