First, telling and/or appreciating sexist or sexual jokes may reflect a broader set of other problematic attitudes and behaviors. Enjoyment of sexist humor has been found to correlate with sexist attitudes (Greenwood & Isbell, 2002); at the outset, this shows that a sexist joke is never “just a joke.” More disturbing and surprising, perhaps, is that appreciation of sexist humor is also associated with increased endorsement of “rape myths” (the perception that women secretly want or deserve forced sex), rape likelihood (reported likelihood of engaging in forced sex if they would not get punished), and with reported sexual aggression in dating relationships among men (Ryan & Kanjorski, 1998). Second, exposure to sexist/sexual jokes may activate or prime problematic behavior; research has found that men who are higher in sexism who hear a sexist joke also report higher rape proclivity compared to those low in sexism or who are not exposed to sexist jokes (Thomea & Viki, 2013). Ford and Ferguson’s (2004) prejudiced norm theory of disparagement humor contends that rather than introducing new prejudices to a listener, jokes serve as tacit permission to express existing problematic attitudes. In other words, sexist (racist, homophobic, anti-fat, etc.) jokes may both reflect as well as impact antisocial attitudes and behaviors.

Enjoyment of sexist humor and accompanying sexist or aggressive attitudes are not exclusive to men—my own research shows that women high in hostile sexism (which captures perceptions of women as manipulative and oversensitive) found sexist jokes as amusing as men high in hostile sexism. Other work also finds that women who appreciate humor also endorse problematic attitudes (e.g., acceptance of violence against women). Particularly noteworthy is that when women tell sexist jokes, they may have an even greater disinhibiting impact on sexist men's attitudes towards rape than when men tell them (Romero-Sanchez et al., 2017). However, research also finds that in general women score lower on measures of sexism (not surprisingly) than men, report more negative responses to sexist jokes, and are less likely to engage in sexual harassment and aggression than men.

One obvious way to shift social norms back in the direction of human decency is for us to speak up whenever we hear someone saying something inappropriate. To say, “Hey, that’s not funny” or “Why are you making a joke about women’s intelligence/bodies/etc.?” However, this far is easier said than done. Why? First, humor cues us to adopt a non-critical mindset and alerts us that we are not supposed to take the joke or the joke-teller seriously. Indeed, recent work (Mallet et al., 2016) shows that compared to sexist statements, women who were sent a sexist joke by a male via instant messenger were less likely to believe he was sexist, less willing to confront him about the sexist content, and more tolerant of sexual harassment in a subsequent measure. In other words, the joke format desensitized the women to the problematic nature of the joke content. If we do confront a joke-teller, we run the risk of being shamed for being over-sensitive and refusing to “play along”  (“can’t you take a joke?!” already a stereotypical predicament for women). Because humor also functions as a form of social dominance as well as a mode of ingroup bonding, boys and men may face a different kind of pressure to play along. Appreciating sexual disparagement of women may also be motivated by a desire to affirm male heterosexuality in the face of threat (O'Connor et al, 2017).

In addition to the above social conventions of humor that can pull for laughter or silence in the face of a sexist joke, avoiding social ostracism per se is an incredibly primitive and powerful motivation for behavior. It’s so powerful, in fact, that when participants are playing a ball toss game on a computer against a group they find repellent (in this case, the Australian branch of the KKK, as labeled by the experimenters, Gonsalkorale & Williams, 2007), they report significant decreases in mood, self-esteem, and even “meaningful existence” if the ostensible KKK players suddenly stop tossing them the ball. The researchers theorize that the pain of social exclusion trumps the intellectual acknowledgment that one is being excluded by a hated outgroup, at least in the short term. (The paper is aptly named: “The KKK Won’t Let Me Play.") Other research in social neuroscience has underscored the extent to which social pain and physical pain are related phenomena by showing neural activation in areas associated with physical pain in response to being primed with social rejection (e.g., Kross et al., 2011). Researchers note that social belonging and survival have been inextricably linked in our evolutionary past.

Speaking out against even mild forms of inappropriate behavior can activate anxiety about social exclusion or ridicule; therein lies the deceptive power of humor. It is easier and safer, by far, to let inappropriate comments go unremarked. But this sends false feedback to the perpetrator that his (typically) behavior is acceptable. Not wanting to be ostracized can lead us to protect the self-image of the very individuals whose behavior should be singled out in a negative way. In fact, feeling guilty or embarrassed for telling an offensive joke is an adaptive way for joke-tellers to regulate their future behavior, particularly if they had been unaware of its offensive nature.

Importantly, failing to respond negatively to a sexist joke also sends false feedback to others who may be stifling their own negative reactions in kind. This can create an environment of “pluralistic ignorance”—a social dynamic in which we incorrectly take others’ responses at face value, failing to account for the ways in which discomfort or confusion may also be inhibiting them as well. [This happens all the time in a classroom setting when in response to the query: “Does anyone have any questions about the material?” not a single hand goes up. Students may look around the room, see that no one else has a question, and decide they must be the only confused person in the room, underestimating the extent to which other students are making similar miscalculations.]

So the deck seems stacked against an easy fix. What to do? Luckily, there is a bright side to our tendency to conform to those around us: Just as we are moved to silence or sexism in the face of others’ seemingly complicit behavior, we are also liberated by dissenting voices. Milgram’s unexpectedly high obedience rates for willingness to shock a (confederate) stranger fell dramatically in the presence of a disobedient confederate (from 63 percent to 10 percent). And hearing just one person in the group depart from the other obviously incorrect responses in Asch’s line estimation study reduced the frequency of participant public conformity (from 30 percent to 5 percent). More recent studies have found that cyberbullying can be countered by priming dissenting voices as well. Hearing one person speak out against a sexist joke can break the social spell of approval and pave the way for others to respond in kind. This is particularly important for boys and men to do, no matter how high the fraternal pressure may be; the persuasive power of someone who is not presumed to be speaking in their own direct self-interest is greater than someone who is (i.e., women, once again in a bind).

As so many of us continue to reckon with the #metoo moment, it is easy to feel daunted by thoughts of #whatnow? In addition to supporting and voting for structural change and accountability at a concrete level, we each have the potential to shift micro-social norms, one joke at a time, if we are willing to be temporarily uncomfortable and risk social disapproval. This is not to diminish the very real social, economic, and psychological pressures that may accompany speaking out against workplace superiors, in particular. But we can begin to explicitly recognize that sexist and sexual jokes may provide a gateway to sexual harassment and sexual assault. We can take pride in understanding it’s not “just a joke,” in taking “jokes seriously,” and believing that sexism is “no laughing matter” (to parrot some of the titles in this line of work). If you hear something, say something.