For most men, football provides comradeship, a sense of community and experiences of excitement and adventure. It also allows the release of youthful aggression through innocuous, albeit often immature, physical exploits.

But among some players football also has a dark and dangerous side. This side of football culture is the one that perpetuates male supremacy and female inferiority. It is a culture that encourages violence against women, including rape, long recognised in American football, now breaking news in Australian rugby league and Australian rules, and not unheard of in New Zealand.

In their own company, men (and, indeed, women) joke about the opposite sex, including their anatomy and sexual activities, appetites and affinities. Among men, talk in team changing-rooms is often sexist.

Slang terms for female genitals are common terms of abuse hurled at teammates who don't measure up, while metaphorical gang rapes have a long tradition in rugby skits and ballads. The Gang Bang Song, a rugby ballad, celebrates men physically conquering women.

Most people dismiss this language and behaviour. They insist it is fleeting and confined to male situations - locker-rooms, bus trips, stag nights. They will tell you it does not reflect the true values of the participants, and that it certainly never translates into actual violent abuse of women.

Yet there are few records of individuals challenging such behaviour. Like scaffolding that holds a building in place, teams exert relentless, unyielding pressure on members. Individuals simply cannot escape sexist comments or behaviour; they must conform and prove themselves.

One gay footballer, who is particularly aggressive and hostile on the field, says he feels "compelled to go along with a lot of the change-room garbage because I want the image ... and a lot of others do, too". He's aware of other players who "like to paint and play the piano, but they do it quietly because they feel threatened if others know".

Substantial evidence suggests that years of immersion in this culture desensitises players in their relationships with women. Strong women who stand up for themselves are a rare species in football culture.

Occasionally, sexist epithets, jokes, songs and skits cross the line of acceptable behaviour and become the foundations of a violent culture that includes physical assault and rape.

What causes this destructive culture? Some critics say that male aggression against women is about dominance, hostility, punishment and revenge. But football teams - like military and police units, and biker gangs - are brotherhoods, what sociologists call fratriarchies. Individuals in brotherhoods must participate in machismo and mean behaviour to consolidate their positions and to express their loyalty to the "team".

Group violence against women within brotherhoods is about young men establishing camaraderie, rapport, fellowship and co-operation.

Football compounds the violence. Football teams consist of intensely competitive males who chase prestige among peers through physical prowess. Voicing anti-female sentiments and violence are an extension of the competition.

A gang-rape situation is a way of meeting the challenge of performing in a group. It's like passing the ball on the field: the "player" must not only control the woman, he must control his own performance. "Control" elevates him up the hierarchy.

While football teams are peer-based groups in which individuals are mainly out to win prestige and honour from their brothers, players also enjoy special bonds with the public.

Footballers provide action, entertainment, excitement, drama, catharsis, escapism and identity. In return the public offers rewards and confers status. So powerful is this relationship that the public willingly turns a blind eye to obnoxious off-field behaviour. Alternatively, they ignore the sexism and violence or blame it on individuals whom they label deviants and abnormals.

American sociologist Peggy Sanday concluded her study of gang rape in fratriarchies on a pessimistic note: "Sexism is an unavoidable byproduct of a cultural fascination with the virile, sexually powerful hero who dominates everyone, male and female alike."

For Sanday, football is just another means of bringing men together, and keeping men together by putting women down.

The crisis in Australian rules and rugby league, paradoxically, offers some cause for optimism. The culture survived because victims (and the press) remained silent. Today new attitudes are removing the shield of protection.

In Germaine Greer's words, women are "not embarrassed to say that they agreed to sex with one man they'd just met, or even with two, but they insist that they hadn't agreed to being brutalised, insulted or humiliated, and they want redress".

Whatever the source of this attitude - feminist movement, higher education, new employment opportunities, single parenting - changes in sport have also helped.

Professional sport has made many young men extremely wealthy and their off-field indiscretions make them, and their clubs, vulnerable to claims for compensation and for large pay-offs in return for staying silent.

Three Australian rules footballers, for example, have admitted paying a woman A$200,000 to keep quiet after she accused them of raping her.

Speaking out is a powerful way to break down cultures of violence within brotherhoods, and it is especially effective when accompanied by demands for financial compensation.

* Douglas Booth is a professor of sport and leisure at Waikato University.