Age and atheism: Eyeballing the 11,000 responses given by participants in the General Social Survey to the question about belief in God, it looks like the percent who are atheists begins to drop in the 50's age range. But visual inspection isn't very trustworthy, so let's divide people up into under age 50 (N= 6,819) and 60 plus (N = 2,594).
What we get is 2.6% for the younger group (CI: 2.2-3.0) and 1.9% for the older group (CI: 1.4-2.4). Now the confidence intervals do overlap a bit, but readers know that I don't fret too much about statistical significance on this exploratory blog.
If we regress confidence in the belief in God on age, we see a small positive relationship (B .01, Beta .08, T-statistic 7.84, p = .000, R-squared = .01). So it looks like atheism slips a bit as one begins to approach that Great Beyond. It's probably due to fear and hedging one's bets, but I suppose it could be a reconsideration of views developed during one's audacious youth.
(By the way, I didn't realize the percent of Americans who are atheists (of whatever age) was quite this low. I thought it was on the order of 5%, but perhaps surveys throw in agnostics.)