Religion is all about being good. The critical question is: To whom? A recent review of the scientific literature on religion and morality argues that our evolutionary past may hold the key to understanding why religion can bring out the best and worst in us.
Much to the annoyance of angry atheists, there is considerable evidence that religion encourages cooperative, pro-social behavior. Studies show that religious people engage in more charitable giving, volunteerism and civic involvement than their non-religious counterparts. Religion facilitates self-control which translates into lower rates of delinquency, criminality, substance abuse, promiscuity and divorce. When reminded of religious concepts, people are more generous, honest, trusting and trustworthy. Finally, religious groups tend to be more cohesive and enduring than non-religious ones.
But take heart, angry atheists, for the evidence is not all positive. For example, increased religiosity -- especially of the fundamentalist variety -- has been associated with more intense prejudicial attitudes. Both covert and overt prejudice against African-Americans increases when people are reminded of Christian concepts. Religion can also increase aggressive tendencies or hostile attitudes against perceived competitors or out-group members and in some instances intensify vengefulness.
In an attempt to make sense of this seemingly conflicting evidence, social psychologist Jesse Preston and her students (Social and Personality Psychology Compass, 4, p. 574) argue that a distinction must be made between two guiding principles of religious pro-sociality: A religious principle, where moral concern is primarily targeted at protecting the integrity of the religious in-group; and a supernatural principle where moral concern is focused on following divine laws of virtuous behavior.
The religious principle emphasizes the communal aspects of religion, where traditions, rituals and distinctive behaviors (e.g. keeping kosher, wearing a turban) mark and unify members of the religious community. A constant threat to any community, including religious ones, are free-riders -- individuals who attempt to reap the benefits of community membership without making necessary contributions. To remain viable, all communities must find ways of thwarting free-riders. Excluding them from community benefits, such as the monetary and emotional largesse of the group, can be an effective control mechanism.
Thus, a thriving religious community must be able to clearly distinguish "worthy" in-group members from "unworthy" out-group members and predominately dispense their moral concern amongst the former. This would explain why studies have often found that religion facilitates pro-social actions toward some people some of the time but not everyone all the time. Being "good" to members of one's religious community often means being indifferent or even antagonistic to those outside the community. Taken to its extreme, the religious principle is the motivation behind the bin Ladens and Torquemadas of the world.
The supernatural principle involves adherence to divine laws of virtuous behavior. Virtuous behavior includes anything believed to be pleasing to or required by one's God (or gods). Typically virtuous behaviors are such things as being honest, charitable, just, compassionate and temperate. The supernatural principle is the basis for the universal love motivating the Ghandis and Mother Theresas of the world.
So what are origins of these two principles? It is here that evolutionary history becomes relevant. In the deep past, the religious and supernatural principles probably overlapped considerably if not perfectly. For example, one might believe that God requires that virtue be restricted to one's religious community and that enmity be demonstrated to out-group members. In small tribal communities, interactions with out-group members would have been rare. The neighbor that one was supposed "to love as oneself" would almost always have been a fellow religious in-group member.
However, as societies grew larger and more complex, the religious and supernatural principles would have increasingly diverged. A more universalist understanding of virtue was probably essential as interactions with both out-group members and widely-dispersed co-religionists became more common. Jesus' parable of the Good Samaritan, for example, redefines "neighbor" in a way consistent with the supernatural principle (anyone in need) and in stark contrast to the religious principle. It is also of more than trivial significance that this parable emerges at a time when Jews were both widely dispersed across the Roman Empire and interacting regularly with non-Jews. Just as the religious principle may have been essential in successfully broadening community beyond just kin, the supernatural principle may have been critical in moving us from tribes to nations. Indeed, research has found that as societies grow larger and more complex, their tendency to envision moralizing gods increases.
How well does the supernatural vs. religious distinction hold up under scientific scrutiny? In their review paper, Preston and her colleagues describe a study where subjects are given the opportunity to cooperate with either an in-group or out-group member (defined by racial/ethnic identity). When reminded of concepts associated with "religion," subjects showed increased cooperativeness with in-group members. However, when reminded of concepts associated with "God" they showed increased cooperativeness with out-group members. A similar finding was obtained when it came to choosing to contribute to a charity. When reminded of "religion" people gave more to a domestic charity, when reminded of "God" people gave more to a foreign charity.
Religious morality (indeed all morality) struggles with an ever-present tension between universalist ideals and the gritty practicalities of human social life. Outside of kinship, religion is humanity's most potent mechanism for building social cohesion. Common rituals and traditions are the social glue of religious communities, binding them together while clearly defining their boundaries. Deep moral concern thrives within but not beyond these boundaries. Religion, however, did not invent bounded moral concern. It is inherent to the human psyche. The family, clan, tribe and nation have, throughout all of human history, taken moral priority over the stranger. In order to have some confidence that the stranger was not a dangerous free-rider and could therefore be invited into the circle of moral regard, humans have historically employed either common gods or common enemies. If the gods are now outdated, are common enemies all we have left?