Our ancestral environment lacked the institutions that now entice us to nonadaptive choices, such as religious orders, adoption agencies, and pharmaceutical companies, so until very recently there was never a selection pressure to resist the enticements. Had the Pleistocene savanna contained trees bearing birth-control pills, we might have evolved to find them as terrifying as a venomous spider.Steven Pinker. How the Mind Works. New York: W. W. Norton & Company, 1997.
Stumbled across that quote awhile ago, but was prompted to post it after seeing this discussion at God is for Suckers!