CB93 is right, there are some specific aspects to American culture and society that most other industrialized countries don't share. Here are some of the main ones relating to the issue of homicides:
-Extremely high incarceration rate:.
High incarceration rates are at first glance more of a symptom of violent society than a factor, but there is also a feedback loop as prison culture reinforces that culture of violence.
-Militarized society. With the exception of the 1980s, major wars in every decade, typically involving brutal occupations halfway around the world (Vietnam, Iraq etc). While these wars were removed from the average citizen, they do shape the lives of the veterans, and some of that violence will spill over.
- very high rates of single parenthood and fatherlessness, especially among minorities. There is a very high correlation rate between fatherlessness and violent crime:
https://www.theatlantic.com/magazine/archive/1993/04/dan-quayle-was-right/307015/Key quote:
Quote:
The relationship [between single-parent families and crime] is so strong that controlling for family configuration erases the relationship between race and crime and between low income and crime. This conclusion shows up time and again in the literature. The nation's mayors, as well as police officers, social workers, probation officers, and court officials, consistently point to family break up as the most important source of rising rates of crime.
-Mass media culture of violence. Yes other countries do get the same films, music and TV series, but Americans in general are more exposed to it, and are more malleable as a culture than say Japan or France, which have much older cultures and more cultural inertia.
-Neoliberal, capitalist ethos pervades the culture, a more cutthroat culture with high inequalities, not much of a social net. Individualistic culture with devalued family values and rootlessness. Anti-collaborative "survivor" mindset, corporate mindset, low-trust society. Contrast with Canada, which has essentially the same mass media but a different social structure.
-Pervarsive mental health issues. Overmedicated culture, big pharma has a lot more sway than elsewhere, starting from early childhood
Many of these factors are inter-related, for instance the media promotes a less collaborative culture (Survivor, Hunger Games etc), and the unbridled corporatism feeds the MIC and prison industrial complex.
The US combines many of the worst elements from other countries with high crime rates: inequalities of Mexico or Brazil (the US now has the same Gini index as Mexico), incarceration rate close to Russia's, gang culture of Central America,...
Bottom line, it's a bit more complex an issue than just gun ownership rates, and the sectarian approach blaming the NRA obscures those factors above.