Actually rape is about power, power over the victim, and the power the rapist percieves himself to have from the act, often it is a crime of opportunity, especially in this country, and it is also seldom reported due to the shame of the victim and the humiliation they go through in the hands of the authorities.
Part of the problem , is that we lived in a sexually repressed society, that is suddenly emerging into an open society sexually and especially with the safe sex campaigns, sex is no longer personalised, but marketed, public figureheads are no longer role models of good sexual behaviour or conduct, and most of the family structure has broken down, not to mention the traditional tribal structure with people flocking to cities in the desperate desire to find work, frustration sets in and people turn to crime to supplement their needs, the violence is a result of "if they are dead, they cant identify me" mentality, normally potrayed in the cheap violent gang related movies that flood the cinemas or video stores in the less upmarket areas, and which most of the slum residents identify with, why?, lack of education and basic services dont exist, gangs rule and people join because it affords them a sense of power in a world of dog eats dog, and gangs offer security of sorts to its members and affiliates, nothing more than smaller versions of the tribal system actually. "Chieftan, generals and soldiers" each group trying to outdo the other for territory and power.