It's really only violence if it is man vs. woman.

[noamnety]

56. Why violent crime is decreasing

I don't have a definitive answer, and don't think anyone does. But wikipedia lists the primary theories, and while they aren't a reference I'd site for an academic paper, it's a good start point on theories:

The number of police officers increased considerably in the 1990s.
The prison population has been expanded since the mid-1970s.
Starting in the mid-1980s, the crack cocaine market grew rapidly before declining again a decade later. Some authors have pointed towards the link between violent crimes and crack use.
One hypothesis suggests a causal link between legalized abortion and the drop in crime during the 1990s.
Another hypothesis suggests reduced lead exposure as the cause; Scholar Mark A.R. Kleiman writes: "Given the decrease in lead exposure among children since the 1980s and the estimated effects of lead on crime, reduced lead exposure could easily explain a very large proportion—certainly more than half—of the crime decrease of the 1994-2004 period. A careful statistical study relating local changes in lead exposure to local crime rates estimates the fraction of the crime decline due to lead reduction as greater than 90 percent.

The first two don't address causes for the violence, only causes for the decrease (locking up people before they can commit repeat crimes). It would benefit people in general - and men in particular, given incarceration rates - if we could reduce the violent tendencies before they turn into prosecutable crimes.

The drug link seems self-explanatory.

The abortion link is interesting, with an assertion that the states with the earliest legalized abortion had the earliest decreases in crime, that drug usage as a cause doesn't hold up statistically because the drop happened across the board even in areas that never had a major drug problem to start with. They claim that "states with high rates of abortion have
experienced a roughly 30 percent drop in crime relative to low-abortion regions since 1985" and legalizing abortion accounts for up to 50% of the reduction. http://www.bepress.com/cgi/viewpdf.cgi?article=1028&context=blewp&preview_mode=
The drop is in people coming of age in the 90's - in other words, the first generation born when unwanted births were able to be legally terminated. So that's a strong argument for both men and women to actively fight for women's rights - it reduces violence against both men and women.

Lead poisoning is a big issue around my area, metro-detroit. "More than half of the students tested in Detroit Public Schools have a history of lead poisoning, which affects brain function for life, according to data compiled by city health and education officials. The data also show, for the first time in Detroit, a link between higher lead levels and poor academic performance. About 60% of DPS students who performed below their grade level on 2008 standardized tests had elevated lead levels." http://www.freep.com/article/20100516/NEWS01/5160413/High-lead-levels-hurt-learning-DPS-kids

Of course, no child left behind ignores the cause and lists those schools as failing and blames the teachers, and republicans look at Detroit and come up with racist theories, I think you alluded to those in your final question. And I don't know anyone who puts the blame squarely where it belongs - CEOs who got rich off lead smelting plants and then engaged in white flight like everyone else once they trashed the area. That's not cultural in the sense we're usually talking about when we discuss a culture of violence, but it points to a strong connection between environmental policies and feminism, if we're looking to reduce violence against women, and an equally strong connection between the environment and men's rights if we're discussing violence against men or incarceration rates.