The answer to this question comes from chapter 6 of Gladwell's examination of why certain people, ideas, or organizations are successful when others are not.
In this chapter, Gladwell describes how the Southern culture of honor explains why certain violent trends in the American South persist in contemporary times. Gladwell explains how family feuds are a pattern in rural Appalachia, illustrating how a distinct culture of honor took shape.
Gladwell states that the early settlers in this region of the United States were direct descendants of Scotch-Irish herders, who used fear and respect to protect their livestock from those who might dare to try stealing from the herders. This cultural inheritance affect modern-day mountain inhabitants.
Similarly, cultures of honor often take root in places that are isolated, like the Appalachian South. Gladwell says that when individuals feel their reputation is their only valuable possession, they are often willing to defend any potential attacks against it, even resorting to violence.
Gladwell explains that the South boasts the highest per capita murder rate of any region of the United States, despite having lower instances of robbery. Gladwell suggests that this is due to the culture of honor in the South. He posits that violent offenders in the South are not motivated by economic forces but rather by self-preservation or tribalism. In this way, the Southern culture of honor is directly connected to violence.