The Bible proclaims "If you believe, you will receive whatever you ask for in prayer" (Matthew 21:22) and "Ask and it will be given to you.... For everyone who asks receives" (Luke 11:9-10). Adherents of the Christian faith and other religious traditions are quite convinced of the power of prayer. Whether it is a family member getting well, a home run during the baseball game, or a new job offer, many people perceive that someone out there is listening to them. However, once you review the evidence, the effects of prayer appear to be entirely psychological.
Confirmation bias is the tendency of individuals to selectively seek information that confirms their pre-existing beliefs while ignoring or undervaluing that which contradicts them. According to psychologist Thomas D. Gilovich, "the most likely reason for the excessive influence of confirmatory information is that it is easier to deal with cognitively." In other words, we generally wish to prove that which we believe to be true, because it would be harder to accept being wrong. This bias has several manifestations and implications with regard to prayer:
- Evidence that prayers were "answered" tends to outweigh evidence suggesting they were "ignored."
- Prayers that were presumably answered tend to be recalled more easily and frequently than ones that were not.
- Theists who primarily focus on the "answered" prayers discuss their experience with others who also believe their prayers are regularly answered. This reinforces and compounds the belief among those in the immediate and greater community.
Ignorance of statistical probabilities tends to lead to a greater degree of confirmation bias in praying theists. Generally speaking, people will pray for things which are fairly probable. When these likely events do occur, they serve as a regular affirmation to theists that God is answering their prayers. On the flip side, when something improbable occurs after a prayer, some theists consider it irrefutable proof of divine intervention. What most people never realize is that improbable events happen all the time. Planes crash, lotteries are won, the worst sports teams beat the best sports teams, etc. Every day in our lives, things occur which have never occurred, and which we never thought could occur. However, when it's something of emotional significance which also relates to the contents of a prayer, people tend to automatically presume a causal relationship. As my old statistics teacher once drilled into my head, "correlation does not infer causation." In addition, given confirmation bias, these unlikely "hits" tend to overshadow the much more numerous "misses" with regard to prayers for improbable outcomes.
The Placebo Effect
According to MedicineNet.com, the placebo effect is "a remarkable phenomenon in which a... fake treatment... can sometimes improve a patient's condition simply because the person has the expectation that it will be helpful. Expectation plays a potent role in the placebo effect. The more a person believes they are going to benefit from a treatment, the more likely it is that they will experience a benefit." This phenomenon is testament to the power of human psychology. Here are just a few fun facts about the effect which show just how powerful expectations can be:
- Fake surgeries can sometimes be just as effective as the real thing
- Yellow placebos help best with depression, green helps with anxiety, and white pills sooth stomach issues like ulcers
- Placebos not only produce the preferred effects of a treatment, but they can also induce expected negative side-effects as well
- People can become intoxicated off of a placebo
In the New Testament, Jesus cured those who had faith in him, as did his disciples. Today, the tradition of faith healing continues to be prevalent, as people pray for health more than any other purpose. In some Christian sects, faith healers claim to have a special connection with God, allowing them to heal the sick better than traditional medical treatments. Given the prevalence of this phenomenon, it's hard to believe so many would buy into it if people didn't believe they were getting better. However, couldn't the benefits of prayer be the same as those produced by the placebo effect? Certainly both seem to require that individuals fervently believe in the treatment/prayer in order for it to work properly. As the American Cancer Society explains, "When a person believes strongly that a (faith) healer can create a cure, a "placebo effect" can occur. The placebo effect can make the person feel better, but it has not been found to induce remission or improve chance of survival from cancer."
Does Prayer Work?
There have been many prayer studies throughout the years which have sought to control for the placebo effect by focusing only on intercessory prayers (IP). That is, prayers done on the behalf of others sometimes without the knowledge of the subject of the prayer. While there has been much publicity around studies which showed that prayer had a substantial effect, these have all been soundly criticized for having severe methodological issues. In 2006, the largest and most meticulously scrutinized prayer study was published, which sought to overcome flaws in earlier investigations. The study split 1,800 cardiac patients into 3 groups: 1) those receiving IP without their knowledge, 2) those receiving IP and being notified they were being prayed for, and 3) those who received no prayer. Researchers then accounted for those participants who experienced health complications within 30 days of coronary artery bypass graft surgery. The results: 52% of those who were prayed for without their knowledge had health complications vs. 59% of those who were told they were being prayed for, and 51% of individuals that were not prayed for had complications. In short, the IP did not have any effect.
Well, the people who were praying just didn't have enough faith...
Alright, it is possible the prayers weren't impassioned enough. Maybe there needed to be a stronger spiritual connection between the prayer and prayee. Consider the study which showed that in the past 30 years, over 200 children have died because their parents relied on faith healing instead of conventional medical treatments? Surely, you'd need to have a great deal of faith in order to avoid proper medical treatment for your child, with whom you would presumably also share a deep spiritual connection.
Okay, maybe God expects you to seek medical treatment when it's available, but what about when it isn't? Consider the case of Nigeria, which is known for its awful healthcare system. It is the 2nd most religious country in the world; it has the 14th highest infant mortality rate, and the 11th highest malaria death rate. I'm not suggesting the religiosity led to the malaria and infant mortality. The lack of proper access to healthcare is a sufficient explanation by itself. However, given their religiosity, you can imagine just how fervently they must pray for their sick and dying. You can imagine in particular, just how hard mothers will pray for the lives of their dying children. In the end, they die just as though no one was listening.
When reviewing the evidence, it seems apparent that prayer just doesn't work. While many theists may be capable of coming up with personal anecdotes regarding the efficacy of prayer, confirmation bias, statistics, and the placebo effect sufficiently explain their beliefs and experiences.
Good video about science and prayer
Good placebo video
Great book about prayer studies