A quick glance at one of my university's periodical databases produced three studies showing that communities and nations with more ethnic diversity have more violence. This isn't the least bit surprising, but you'll never hear it talked about by the MSM as an important reason why the U.S. has a high homicide rate, or how perhaps diversity is a burden, not a godsend.
1. Osgood, Wayne et al. 2000. Criminology.
2. Roundtree, Pamela et al. 2000. Criminology.
3. Hoskin, Anthony. 2001. Justice Quarterly.