AUBURN, Alabama -- Researchers at Auburn University, who are searching for the evolutionary source of religion in human societies, say biological factors may play a key role in shaping our religious beliefs.

In a new paper published in the scholarly journal "Brain Connectivity," they propose religious belief involves specific regions of the brain and that an individual's religiosity depends on how those regions communicate.

Their findings that the brains of religious and non-religious subjects work differently suggests that religious belief may have evolved over thousands of years like other human traits such as language, according Gopikrishna Deshpande, the lead researcher and an assistant professor in Auburn's electrical and computer engineering department.

"Religious belief is a unique human attribute observed across different cultures in the world, even those cultures which evolved independently. ..." he said. "This has led scientists to speculate that there must be a biological basis for the evolution of religion in human societies."

Teaming up with the National Institutes of Health, Auburn researchers used functional magnetic resonance imaging or fMRI to observe the brain activity of self-declared religious and non-religious subjects as they contemplated religious belief.

They found that an individual's religious belief depends on three cognitive dimensions: (1) God's perceived level of involvement in the subject's daily life, (2) God's perceived emotion, and (3) the subject's doctrinal or experiential knowledge of religion.

They also found that those cognitive dimensions can be mapped to specific regions of the brain.

While scans showed the amount of brain activity does not vary between religious and non-religions subjects, they detected notable differences in the way those brain regions communicate.

In their findings, the researchers said subjects who perceive a supernatural agent at work in their daily lives tend to use brain pathways associated with the regulation of fear when asked to contemplate their religious beliefs.

And subjects with religious beliefs based on doctrine, such as knowledge of religious scripture, tend to use pathways associated with language when they contemplate religion.

However, non-religious subjects tend to use pathways associated with visual imagery when they contemplate religion, according to the study.

Deshpande said those finding suggest subjects with a greater capacity to imagine visual images are less likely to be religious.

He proposed that those subjects attempt to visually imagine a supernatural agent as a test of its existence and subsequently reject the idea as unlikely when that image does not fit with any known image in their memory.

The researchers also found individuals with a stronger ability to attribute mental states -- such as beliefs, desires and intents -- to themselves and understand that others may have different mental states tend to be more religious.

The ability to attribute mental states, known in scientific communities as the "theory of the mind" is thought to have evolved in humans over thousands of years, according to Deshpande.

He said that finding supports the hypothesis that the evolutionary development of that ability in humans may have given rise to religion in human societies.

According to Deshpande, the findings do not mean that an individual's religious belief is completely dependent on biological factors. Instead, he said it is likely a combination of biological and social factors.

In fact, he said, social factors can influence the development of brain pathways.