Religion has been with us as long as there has been human civilization, if not longer. Conversely, for as long as there has been human civilization, religion has been a battleground, both real and theoretical. Even today we see it in fanatics killing those with whom they disagree or the advent of the so-called “new atheism . Too often lost in both the pervasiveness of religion and the commotion it can generate is the key question of its purpose.
Lionel Tiger and Michael McGuire are among the latest to investigate and opine on the answer to that question. At bottom, the one they provide in God’s Brain  is quite simple. Taking the position that any one religious belief or total lack thereof is immaterial to finding the answer, they conclude that the purpose of religion is to “brainsoothe.” In other words, religion exists to help the brain deal with both internal and external stress and anxiety, something they call “brainpain.”
Tiger and McGuire are not the first to analyze the brain’s role in religion. Some have argued that religion is an evolutionary tool so humans can cope with knowing death is inevitable , an awareness other species do not possess. Others debate  whether the brain specifically originated religion or if it is simply the result of neural connections that evolved for other purposes. Still others question the whole idea that religion may be “hardwired ” into the brain, containing it is simply a sociological adaptation. Tiger, a professor of anthropology, and McGuire, a psychiatrist and neuroscientist, combine their expertise and ultimately conclude the brain is both the source and principal beneficiary of religion.
God’s Brain is meant for a lay audience. The authors frequently express their concepts in simple, everyday terms. For example, “Religion is to the brain what jogging is to the legs.” Even those of us who can barely cope with chemistry for dummies can grasp that concept. That may be in part due to the fact they are dealing with a subject that has far less empirical data than other subjects. Still, McGuire and Tiger invoke a wide range of social and “hard” sciences, whether brain chemistry or the study of nonhuman primates. Although the range can make the material somewhat kaleidoscopic at times, they do not let the book become too abstract or academic.
Essentially, McGuire and Tiger see religion as a coping mechanism for the brain to deal with anxiety, fear and stress. They argue that the socialization, rituals and beliefs that make up religion help the brain alter itself, to “brainsoothe.” To some extent, their contention turns religion into a self-sustaining system. “As oxygen is to air, guilt is to religion,” they observe. Yet what is one way the brain copes with guilt? Through religious ritual, such as Catholic confession, and belief, such as the forgiveness of sins.
Some, particularly those with a fundamentalist bent toward any religion, may see this theory as an effort to substitute brain chemistry for God. Tiger and McGuire take pains to point out and aim to predicate their analysis on it not being dependent on whether any or all religion is true. They argue that because religion is “as diffuse as oxygen and seemingly as imperative,” we need to attempt to understand it as it is rather than fight over its validity or value. In that regard, even with its occasional weaknesses God’s Brain is a welcome respite from the frenzied cacophony that too often attends discussion of religion.
Religion pleases the brain’s sweet tooth.
Lionel Tiger and Michael McGuire, God’s Brain