Religion today serves many political, social, and charitable functions. Yet it seems unlikely that religion first arose to solve social problems (1). When religious propensities first evolved, they likely emerged because of the advantages to individuals.
For, if the pious person did not somehow fare better than the level-headed skeptic, then religion could never have got off the ground. This means religion aided survival or boosted reproductive success.
So how could early religions have helped our ancestors to cheat death or raise offspring? Either religious people left more offspring or they were healthier and better at surviving. As to health, perhaps religious practices reduced stress thereby improving health and survival (1).
Be fruitful and multiply
To take reproduction first, religion today promotes marriage and family life and increases reproductive success. But religion might not have affected reproduction in the remote past.
More religious people have larger families today. They stick with practices that less religious people have abandoned. They are less likely to use contraception, for example, and more likely to get married.
Yet is seems unlikely that religion had much impact on fertility for our hunter-gatherer ancestors. There were no scientific contraceptives then, of course. In those days the only effective birth control method involved prolonged breastfeeding that suppressed ovulation.
For our subsistence ancestors, fertility could not be arbitrarily raised. The upper limit of family size was fixed by what the local ecology could support. Our ancestors relied partly on hunting so if populations became too big, their prey animals would have died out.
Fertility enhancement is not a convincing explanation for the emergence of hunter-gatherer religions. So what about the other explanation, the view that religion evolved because it helped our ancestors to deal with psychological stress thereby contributing to health and survival?
Does religion provide tranquility in a sea of troubles?
The argument that religious practices help people to deal with the stress of uncertainty is more convincing because the evidence is supportive whether one examines modern conditions or subsistence societies. According to this view, religion provides comfort for adults much as a security blanket does for small children.
We know that people invoke their religion most when they experience difficult and trying circumstances and that residents of developing countries who confront the misery of poverty, hunger, illness, and violence in their daily lives are extremely religious. Hunter gatherers also use religion to help them deal with trying circumstances, such as a string of unsuccessful hunts, or fear of setting out in a small boat on rough waters (1).
Most world religions promise tranquility in the face of a sea of troubles. That is certainly true of the Hebraic tradition that promises a “peace that passes understanding.” This usually refers to the afterlife.
Fortunately, there is a much less onerous variant according to which religious individuals achieve inner peace merely by giving themselves over to that experience. This perspective is movingly portrayed in Psalm 23, (“The Lord is my Shepherd …”) a much-loved Biblical quotation that is often recited by people when they are distressed in order to restore their equanimity.
So religions offer peace of mind. Do they deliver? The most relevant evidence concerns the impact of religious rituals on psychological stress.
Religion as a health plan
Researchers at Duke University (2) found that religious rituals function as an anti-stress mechanism. They demonstrated that individual prayer, as well as attending church services, reduces blood pressure, high blood pressure being a reliable index of psychological stress.
Elevated blood pressure causes heart disease and heart disease is the number one killer in many developed countries. Any practice that lowers blood pressure on a regular basis, whether it is pleasant social interactions with friends, or physical exercise, reduces the risk of heart disease (2). By this logic, prayers and rituals enhance health and lengthen life.
Most world religions promote the view that human life is worthwhile and has a purpose. Such an optimistic frame of mind does wonders for happiness and health. This helps explain why religion is so important in the poorest, most disease-infested countries on the globe.
1. Barber, N. (2012). Why atheism will replace religion: The triumph of earthly pleasures over pie in the sky. E-book, available at: http://www.amazon.com/Atheism-Will-Replace-Religion-ebook/dp/B008...
2. Paul-Labrador, M. D. Polk, J. H. Dwyer, I. Velasquez, S. Nidich, S., M. Rainforth, et al. (2006). Effects of a randomized controlled trial of transcendental meditation on components of the metabolic syndrome in subjects with coronary heart disease. Archives of Internal Medicine, 166: 1218-1224.