This explains a lot
http://www.philly.com/philly/health/132456883.html
Being 'Born-Again' Linked to More Brain Atrophy: Study
"According to the study, people who said they were a "born-again" Protestant or Catholic, or conversely, those who had no religious affiliation, had more hippocampal shrinkage (or "atrophy") compared to people who identified themselves as Protestants, but not born-again."
Perhaps this explains the high correlation between evangelical religious beliefs and conservative political preferences. The question should be, is it causal? And if so, which causes the other?