In 2004, the GSS asked respondents how frequently they "desire to be closer to God or in union with Him". Answers were on a six point scale, ranging from "many times a day" on the high end to "never or almost never" on the low end. The following table shows the mean closeness to God score by age range, the higher the number, the closer to God (values are inverted from the actual survey for ease of presentation):
We get a little more Plato and a little less Aristotle as people get older, but the changes in inclination are slight. A standard deviation for responses is 1.59. The differences between those who are basking in life's morning glow and those who are in its gloam amount to less than one-third of a SD.
This seems to generally agree with the "God gene" framework of human religiosity.
GSS variables used: CLOSRGOD, AGE