We all have our personal "theories" about what motivates religious terrorists. To go from personal theories to real ones, we need to study the issue scientifically. One recent study draws the provocative conclusion that ritual participation more than religious belief may be behind suicide attacks.
From a scientific standpoint a suicide attack represents an extreme form of parochial altruism -- a self-sacrificial act made on behalf of one's in-group, involving aggression against an out-group. Religious belief, some have argued, is the prime motivator for such an attack. The attacker believes that his or her sacrifice will lead to a glorious reward in the afterlife (e.g., Islam's famous 70-some-odd virgins-awaiting). This explanation can be called the "belief hypothesis," and it would predict that those who demonstrate increased devotion to religious beliefs or deities would be more supportive of suicide attacks. In the context of a recent study (Ginges et al., Psychological Science, 20, p. 224), devotion was measured by prayer frequency. Thus, those who prayed more were assumed to be more devoted, and some preliminary analyses confirmed that this was indeed the case.
A second possible explanation is that suicide attacks are motivated by an especially powerful emotional commitment of an individual to his or her social group (called the "coalitional commitment hypothesis"). Past research has established that communal rituals can engender strong group commitments (think of how fraternity initiation rites produce strong bonds among "brothers"). Thus, those who participate more regularly in communal rituals should be more strongly bonded to their groups and therefore more likely to support violent attacks against out-groups. In the current study, attendance at regular worship services was used as the index of one's ritual participation, with the hypothesis being that increased ritual participation should produce stronger support for suicide attacks.
Simply stated, then, the research question becomes: Is it prayer (devotion/belief) or attendance at church, synagogue, or mosque (ritual participation) that more strongly predicts support for suicide attacks? (Note: preliminary analyses further verified that attendance at worship services was either not a reliable predictor of religious devotion or was a significantly weaker predictor than prayer frequency, thus confirming that ritual participation and prayer frequency were tapping separable constructs).
The authors tested these two hypotheses using surveys measuring people's self-reported frequency of both prayer and worship attendance, and their support for suicide attacks (or acts of parochial altruism in general). Surveys were conducted among Palestinian Muslims (both West Bank and Gaza residents), Indonesian Muslims, Mexican Catholics, British Protestants, Russian Orthodox Christians, Israeli Jews, and Indian Hindus. In every sample surveyed it was attendance at worship services that predicted support for suicide attacks and not prayer frequency. Indeed, in at least one subsample (Indonesian Muslims) prayer frequency was negatively correlated with support for parochial altruism; that is, more devoted Muslims were more likely to oppose suicide attacks.
To further validate their findings, the authors conducted an experimental manipulation with Jewish "settlers" living in either the West Bank or Gaza. The study was based on a "priming" paradigm where a subtle, often subliminal, reminder of a particular concept temporarily increases the concept's influence on one's attitude or behavior. For example, previous priming studies have found that if people are reminded of some religious (God, spirit) or legal (court, police) concepts, they act more generously in subsequent economic games. In this priming study, half of the settlers were randomly assigned to a synagogue prime where they were subtly reminded of synagogue worship while the other half were exposed to a prayer prime, where they were reminded of praying to God. After this, subjects were asked if they regarded Baruch Goldstein's 1994 attack on a mosque to be "extremely heroic." Significantly more subjects receiving the synagogue prime (23%) affirmed this statement compared to the prayer prime (6%). Given that 15% of control subjects (unprimed) affirmed the statement, there is an indication here that the prayer prime actually lowered baseline levels of support for Goldstein's attack. Furthermore, note that even among the synagogue prime condition, the vast majority of subjects did not affirm the statement.
There are a number of important lessons to draw from this research. First, as just one study of a complicated issue, it by no means definitively explains suicide attacks. However, it does provide support for the notion that forming group identities and emotionally binding people to those identities are important driving forces behind this behavior. While religious ritual is a highly effective group-bonding mechanism, it is not unique in this respect. Fraternities, military services, and social/political movements make use of the same basic principles and processes. Furthermore, as the authors of this study point out, ritual and group bonding are also fundamental to human community and all the positives associated with that. This research simply highlights the dark, dangerous side of our highly social nature.
Second, this study should give pause to those who trumpet simplistic slogans regarding the religion-violence issue. This issue is not simple. Ritual bonds people to groups, and powerful emotional bonds can heighten support for aggression against out-groups. Religious ritual, it appears, can be particularly potent in this regard. By the same token, however, there is evidence that heightened devotion to religious beliefs may actually curb out-group hostilities. Specifically what beliefs might have this effect and how to further cultivate them are important questions for further studies.
Finally, this research demonstrates that questions about religion and inter-group violence can be addressed scientifically. Strong opinions about religion and its role in promoting or defusing violence are rampant. Far too often those opinions are based solely or primarily on subjective experience, personal feelings, or one's favorite self-serving historical anecdote. Opinions or judgments informed by actual research are far rarer and infinitely more valuable. If contrasting parties on either side of the religious/secular divide are to communicate constructively on this issue, they might start by agreeing to make science rather than slogans the basis for their discussions.