WASHINGTON (Army News Service) -- For some time, through its Sexual Harassment/Assault Response and Prevention program, the Army has asserted that sexist humor is unacceptable in the workplace.

Sexist humor, however, is more than just offensive, according to Dr. Gail Stern. More important than the joke itself, and the immediate effect it has on people who hear it, is the desensitizing effect it has on listeners, she says.

Stern, a researcher, victim advocate and subject-matter expert on sexual assault prevention, spoke Tuesday at the Pentagon about the effects of sexist humor on listeners and how acceptance of such humor affects the social environment.

Stern's presentation involved a selection of anecdotes from her experience as a sexual assault prevention professional, as well as a series of slides featuring advertising that employs rape as a component and rape "jokes."

During her presentation, Stern provided two examples of rape jokes for her audience:

"What do nine out of ten people enjoy? Gang rape!"

"Hello, my name is 'Rape.' Remember it. You'll be screaming it later."

Stern said some people will find such jokes offensive, while others will find humor in them. But the more those types of jokes are told, the more accepting people will become of the subject matter. That type of humor, she said, desensitizes people to rape, and the effect is that rape itself is considered less of a problem.

"The rape jokes -- it's not about sensitivity," she said. "Anybody that tells you it's about sensitivity is full of it. It's not about sensitivity. It's about how it conditions [listeners] cognitively to accept violence and abuse toward another group."

Stern also referred to a number of print advertisements that made light of rape. In one advertisement for a brand of vodka, the text suggests that, unlike "some people," this brand's vodka always "goes down smoothly." The ad's imagery features a terrified woman being grabbed from behind by an amused man.

"What's the joke here?" Stern asked. The woman in the photo, apparently, didn't want what the man wanted. The ad is a play on words in which sexual assault is part of that word play.

Stern noted that advertising executives must have discussed it. "Before they went with this, they were like, 'Guys will laugh at this,'" she said. "Thought went into that. People said OK to that."

Another ad features a man and woman dressed for a party and standing against a white background. The woman, on the left side of the ad, has her head turned and is looking out of frame and laughing as if engaged in a conversation. On the right side of the ad, a man leers at her, as though noticing she is distracted. The ad's copy suggests "spiking" your best friend's drink when she's not paying attention.

"[The advertiser is] not saying 'knife' your best friend while she's not looking," she said. "There's an implication that he'll get out of the 'friend zone' maybe, right? If it's spiked, he'll have an easier time at this party? And that's not considered rape by many people. It's not saying 'roofie.' We'd be like, that's too dark. But 'spike' is sort of neutral enough; we are willing to grant this guy a little latitude."

The Army has been pushing "bystander intervention" training as a way to encourage Soldiers to step up and prevent sexual assault before it happens. Stern identified four factors that must be present for an effective bystander intervention. Those factors are:

1) Notice the situation.
2) Define the situation as problematic.
3) Feel the responsibility to act.
4) Have the skills to act.

The problem with bystander intervention, however, is the assumption that everybody will be able to notice a situation and identify it as requiring intervention. That's not always going to be true, Stern said.

Jokes about rape, and sexist humor, she said, have "numbed our assessment abilities, to the point where we are less liable to ... notice it and ... define it as a problem ... or even think we are responsible to do anything about it if it's not that big a deal anymore."

Rape jokes, Stern said, "make rape acceptable at some cognitive level. If I think that sexual coercion is acceptable or is just a normal part of the culture, I'm going to call it sex. Maybe bad sex. But I'm not going to call it rape."

Stern said it's not necessary, every time a Soldier, for instance, hears a sexist joke, to make "a federal case" out of it. But calling out the teller of such a joke, she said, goes a long way toward ensuring that culturally, in whatever group you are in, rape, sexual assault, and sexual coercion do not become acceptable at any level.

"You do have to say, 'Buddy, come on. Rape jokes aren't funny' ... something that calls out that negativity," she said. "If that person gets approval for it ... if we stay silent, we have cosigned on that. We've said you're good to go. "

Soldiers, Stern said, have a responsibility to challenge such behavior -- the jokes and comments -- as a way of changing what is culturally acceptable.

"In order to create a culture that doesn't tolerate sexual assault, you have to challenge sexism," she said. "And you have to do it at every different stage."

That means not just challenging jokes that make light of sexual assault, she said, but also challenging a Soldier who belittles another's performance because she is female, or who talks about why women shouldn't be in the Army, for instance.