I've been asking myself this question since I've started meditating in earnest in 2009. On the surface, it would appear that meditation is rather conducive to good relationships with others; all this awareness and acceptance of what's going on in the present moment, not to mention the love that people experience when they do the metta meditation. Also, in contrast to most other religious experiences that may give similar outcomes, in meditation practice there is no need for a God-concept that is different from others' God-concepts. This would render it harder to contrast one's God's commandments with the perceived transgressions of some other person. Which in turn would make conflict less likely, or less severe if conflict was indeed encountered.
On the other hand, most of the bad things in the world are done by or through groups of people. Obviously, evil can exist in individuals and this happenstance can be a salient fact for our collective imaginations, as evidenced in the popular culture that has grown up around serial killers, vampires and werewolves. However, group brutality is much more common, and also much more insidious; groups have been shown to be able to commit genocide, perpetrate slavery or encourage child pornography. To be able to understand, then, how the world might or might not change with more people meditating, we need to look closely at social decision making, in order to determine the optimal locus of intervention for meditative practices.
Social psychology has researched and documented social decision making processes and points to tendencies of individuals in groups to conform to group pressure. Group members with relatively mild views have their positions polarised by engaging in group discussions with like-minded people. This is strangely counter-intuitive. Yet studies show that discussion among like-minded individuals tends to increase and intensify pre-existing attitudes and that actions of individuals when in a group are more extreme than when the individual acts on her own.
Merely knowing that this dynamic exists does not inoculate individual group members or the group itself against its ill effects - if indeed they are ill. Apart from agreeing with eachother, individual group members appear to have little control over the ultimate decision; they went in moderate, and came out more polarised. Apparently, at this level of research, we can't really explain anything. Two mechanisms have been suggested to underlie this. Social comparison theory holds that people gain acceptance and leadership by sensing what is the majority opinion and then proposing a slightly more extreme solution. Informational influence theory suggests that by engaging with like-minded people a person hears novel arguments corroborating their previously held views. Because the theory expects people to rationally weigh remembered pro and con information, these novel arguments emphasize the individual's leanings, thus skewing the decision making process towards more polarisation.
At this point, a reasonable assumption would be to require of the groups that we have joined that the opposition opinion is voiced quite as loudly as the majority one. This counter-intuitive measure might safeguard against all-too-zealous action on the part of the group. Yet, this has a danger in itself, of opinion coalescing around the two now opposing viewpoints, they themselves polarising which could lead to a schism, or a breakup of the group. In other words, if a group chooses to safeguard in this manner, it may end up effecting its own dissolution. It's hard to view this as a reasonable course of action for any group to take.
Back to the question with which this piece began. Could meditation help in this process? I must admit that I am not able to see a clear way forward in this regard. I hope to engage you, the readers in this. Any thoughts?