Neuroscientists are uncovering interesting correlations between religiosity, the tendency to feel anxiety and the function of serotonin in the brain. Studies of both mice and humans have documented the important role of specific serotonin receptors in the regulation of mood and anxiety that may underlie our need for spirituality. First, consider the connection between anxiety and a particular serotonin receptor. Mice bred to lack the serotonin (5HT) receptor known as 5HT-1A show more anxiety-like behavior. One very successful drug, Buspar (buspirone), reduces the symptoms of depression and anxiety in humans by stimulating this serotonin receptor. The overall effectiveness of Buspar, and similar drugs, suggests that this receptor in particular may play an important role in the normal control of anxiety.
So what's the connection to one's personal degree of religiosity? Using sophisticated imaging machines, the number of type 5HT-1A serotonin receptors in the brain was discovered to be inversely correlated with self-ratings of religiosity and spirituality. People who respond negatively (e.g., with excessive anxiety or depression) to the challenges of everyday life have fewer 5HT-1A receptors (just like the mice I discussed above) and are more likely to find comfort in religious faith and practice. Moreover, a series of studies have demonstrated that people with certain serotonin receptor profiles suffer more often with social anxiety disorder, which is characterized by an extreme fear that other people are thinking bad things about them. Fortunately, people who have fewer of these 5HT-1A receptors also tend to respond more positively to placebos or affirmative suggestions than people who do not have these types of serotonin receptors in their brain. Taken together, these findings suggest that people who yearn for more spiritual leadership in their lives may have inherited fewer type 1A serotonin receptors than those who never express such yearnings. If true, these data might explain why children tend to echo the religiosity of their parents.
Before drawing too close of a correlation between religiosity and the number of 5HT-1A receptors, recent research has also identified other features of the brain that may also correlate with the tendency to rate one's self as religious. A recent investigation discovered that the tendency to display extravagant religious behaviors correlated significantly with atrophy (i.e., shrinkage) of the right hippocampus in patients with untreatable epilepsy. In fact, the medical literature is replete with reports of epilepsy patients with religious delusions. Furthermore, and quite intriguing for its implications for the typical spiritual experience, are reports that decreased brain activity in the hippocampus has also been correlated with the feeling of a "sensed presence" or the feeling of an unseen person nearby. Recent studies using sophisticated brain imaging techniques also suggest that the prefrontal cortex is more likely involved in controlling our religious, moral, and paranormal beliefs. Although the results of these initial studies are fascinating, neuroscientists are only the infant stages of understanding the nature of the spiritual experience in the brain.
© Gary L.Wenk, Ph.D. author of Your Brain on Food (Oxford, 2010); http://faculty.psy.ohio-state.edu/wenk/