Where does spirituality come from? Social scientists have spent years tracing the origins of various religions, but they have never been able to answer what makes some people extremely spiritual, while others feel no religious calling at all.
Recently, a team of neuroscientists discovered an unlikely answer: How religious you are may be in part influenced by biological factors, specifically, the relative thickness of the cerebral cortex.
The researchers from Columbia University and the New York State Psychiatric Institute noted that those adults who were most strongly connected spiritually displayed thicker cerebral cortices above the left and right hemispheres.
Somewhat surprisingly, the scientists also found that the thickness of cortices was not associated with how often a person attended their church, mosque, synagogue or temple.
Adults between the ages of 18 and 54 were surveyed about the importance of spirituality in their lives and how often they attended religious services. After five years, researchers asked the same questions of all 103 study participants. Then they gave them brain scans.
The team had previously found that people with a strong interest in spirituality were less likely to develop major depression. They had observed a relationship between high risk of depression and thinning across the surface of the cerebral cortices, suggesting that cortical thickness may be a predictor of depressive symptoms.
The finding about cortical thickness is in line with earlier research which showed that staying focused on your personal priorities, including those linked to religion, can offset feelings of mental stress.
The scientists warn that so far their results only show that people who are more religious seem to have thicker cortices, not that being religious or spiritual actually causes certain areas of the cortex to thicken.
The study is published online, ahead of publication, in JAMA Psychiatry.