This article is an in-depth view of whether a religious belief in an higher power is found in particular genes or not.
It has some useful exerts, in which many psychologist have done studies across the board in the attempts to identify in religion is found in our genes. Particular studies have identified that the deeper people go into meditation or prayer, the frontal lobes and the limbic system become much more active, while the parietal lobe goes dim. For those who don't quite remember the functions of these regions, the frontal lobe is a "seat of concentration and attention"; the limbic system is where one find intensive feelings; the parietal lobe "orients the individual in time space."
These experiences all together create a feeling that is "profoundly religious," because it disconnects a person from their sense self and gives them an out of body experience of sorts.
However, regardless of whether the brain or genes can be connected with spiritual feelings, it's questionable if this is connected with how religious a person actually is.
This article also mentions the U of M twin studies, in which identical twins had very similar levels of spirituality, but not necessarily similar levels or religious participation.
Not only is this all a question of nature vs. nurture, is also hits on the disputes of God. Can one really include the use of God in some sort of psychological study, when clearly it is an extraordinary claim, and isn't necessarily able to be falsifiable?
At any rate, I would encourage all of you to further read the article itself, as it entails much more than a blog post can do it justice.
Daniel Williams, et al. "Is God In Our Genes? (Cover Story)." Time 164.17 (2004): 62-72.