According to a new study, certain types of brain injury are linked to an inability to understand other belief systems. But many news reports on the study suggest that it connects to specific “fundamentalist” or “extremist” religious beliefs. Science can do certain things, but this study means a great deal less than many headlines would suggest.

Here’s what happened: Neuropsychologists at Northwestern University studied almost 150 Vietnam War veterans, many of whom had suffered brain damage, and discovered that those with brain injuries were less open to new and different religious beliefs.

“Human beliefs, and in this case religious beliefs, are one of the cognitive and social knowledge stores that distinguish us from other species and are an indication of how evolution and cognitive/social processes influenced the development of the human brain,” the study’s corresponding author, Jordan Grafman, told PsyPost.

Grafman and his team surveyed 149 Vietnam vets, 119 of whom had suffered penetrating traumatic brain injuries (pTBIs) and 30 of whom had no history of brain injury. They reported their results in the journal Neuropsychologia. Previous research had identified the ventromedial prefrontal cortex (vmPFC) as critical to representing religious beliefs, so the researcher hypothesized that damage to the vmPFC would be associated with a narrowing of religious beliefs.

“If the vmPFC is crucial to modulating diverse personal religious beliefs, we predicted that pTBI patients with lesions to the vmPFC would exhibit greater fundamentalism, and that this would be modulated by cognitive flexibility and trait openness,” the researchers explained.

But their results actually contradicted this hypothesis. Instead, Grafman and his team discovered that veterans with damage to the dorsolateral prefrontal cortex (dlPFC) had similar belief patterns to those with vmPFC lesions. The researchers also found that veterans with less openness to other beliefs did not necessarily have damaged dlPFCs — some merely had decreased cognitive flexibility and openness.

Grafman wrote that “these findings indicate that cognitive flexibility and openness are necessary for flexible and adaptive religious commitment, and that such diversity of religious thought is dependent on dlPFC functionality.”

Grafman argued that this study highlights “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 parts of the human brain.”

But the results of this study, like all scientific results, are very limited. “For this study, we recruited Vietnam Veterans with and without brain injuries,” Grafman told PsyPost. “They were all male American combat veterans. This limits the generalization to other groups of people including women, people from other countries, and people who come from cultures with different primary religious beliefs.”

Indeed, that last bit is particularly illuminating. A great deal of this study depends on the definition of “religious fundamentalism.” Rather than any specific type of belief, the study seems to examine an individual’s openness to examining other forms of religious belief.

“Religious fundamentalism” often refers to a specific set of religious beliefs, rather than a general trait of being closed to other viewpoints. Dictionary.com defines fundamentalism as “a religious movement characterized by a strict belief in the literal interpretation of religious texts.”

According to this study, certain types of brain injury may weaken cognitive flexibility — the ability to consider different ideas — in religion specifically. This could mean a strict biblical literalist with a brain injury would be less able to understand an atheist’s beliefs. But it could also mean an atheist with a brain injury would be less able to understand the beliefs of a biblical literalist.

The results in this study do not suggest that a certain type of religious belief — what could be termed fundamentalist Christianity — is the result of brain injury. The study only suggests that those with a specific type of brain injury are less able to grasp beliefs other than their own.

Furthermore, the study does not extend to other types of beliefs. “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 admitted.

“Beliefs have sculpted our behaviors for thousands of years and helped shape the development and sophistication of our brains,” the researcher added. “Such beliefs systems are dependent upon other aspects of our cognitive and social processes and those interactions would be important to understand.”

Indeed, sociologist Rodney Stark has written extensively about how social networks impact religious conversion, and he has theorized that someone converts to a new religion when the social connections with the new faith outweigh that person’s relationships in the previous faith. Stark also explained the concept of religious capital — that knowledge of doctrines, songs, and traditions from the convert’s old religion often shape the faith he or she chooses to convert to.

This brain damage study suggests that certain people are less able to develop new “religious capital,” and that would limit their ability to think like other people — and ultimately harm their ability to convert to other religions.

Brain injury does not, however, predispose someone to think in a certain way. An atheist would not suddenly become a fundamentalist Christian as a result of traumatic brain injury, for example.

The link between brain chemistry and religion is extremely controversial, and it is unlikely science will fully explain why people think they way they do. Nevertheless, there are certain types of discoveries which neuropsychology can make, and it stands to reason that certain types of brain injury would damage someone’s ability to examine alternate belief systems.

None of this disproves any particular belief system — and yes, atheism is a kind of belief system — but it does suggest that some people are more able to consider the beliefs of others. Not everyone is openminded enough to consider other perspectives, but that should be no surprise to anyone.