YOU have applied for a job and the interviewer asks you a question that lands like a bombshell: do you have a boyfriend? Then another: do people find you desirable? And a third: do you think it is important for women to wear bras to work? If you are a woman you probably know what you would do. Perhaps you would refuse to answer, complain or walk out. You would certainly be furious.

This is how 197 female American undergraduates, asked to imagine such an interview, said they would react. But they—and probably you—were wrong. The psychologists who asked them, Marianne LaFrance and Julie Woodzicka, orchestrated a real-life version of this ordeal, by advertising for a research assistant and arranging for male accomplices to interview the first 50 women who applied. Half were randomly chosen to be asked those three questions. Not one refused to answer, let alone complained or walked out. When they were asked afterwards (and offered the chance to apply for a real job), they said they had felt not anger, but fear.

An ethics review board had let the experiment go ahead when it was assured that the interviewers would go no further than off-colour questions. And yet videos of the interviews showed how much this supposedly minor sexual harassment threw the women off their stride. They plastered on fake smiles, ummed and ahhed, paused and trailed off more often than the control group. Ms LaFrance, who studies non-verbal communication, says they “screwed up the interviews”.

In a final twist, the researchers showed clips of the videos to male MBA students. Fake smiles are fairly easy to tell from real ones: they involve fewer facial muscles and do not crinkle the corners of the eyes. But many of the men saw the women as amused, even flirtatious. Men often lack the motivation to read the signs of women’s feelings, says Ms LaFrance. But they can learn if they want to. When she offered course credit to the students who learned to spot the fake smiles, plenty succeeded.

This experiment was carried out in 2001, long before the events of 2017 blew open the extent of sexual harassment of women at work by powerful men. But it was a masterful demonstration of how such abuse works—and of the misconceptions that have enabled it to continue for so long. It revealed the differences between what women think they would do if they were sexually harassed and what they actually do; between the perception of verbal harassment as trivial and the harm it causes to women’s work performance; between women’s and men’s notions of what counts as sexual harassment; and between women’s feelings and men’s perceptions of them.

This year has shown that these differences are still wide. It has seen the long-overdue punishment of some brutish men who had groped and leered their way round their workplaces. But has there been a permanent shift in what society will tolerate? Or will the moment pass, and a new generation of powerful men slyly take up where a previous one left off?

One place to look for an answer is in the way other social norms have changed. From the abolitionists’ fight against slavery in the 19th century, to campaigns against domestic violence in the 1970s, to demands for same-sex marriage from the 1990s, progress comes in stops and starts, with many reversals. Campaigners must defeat vested interests, incomprehension and ridicule. Cristina Bicchieri, a philosopher at the University of Pennsylvania and the author of “Norms in the Wild”, a book about social rules, has a warning: “Don’t expect the birth of a new norm to be easy.”

From the top

With hindsight, this year’s flood of allegations had its source in 2016. During Donald Trump’s presidential campaign, a sound recording revealed him boasting of serial harassment and groping. His election just a month later showed that American politics had become so polarised that this did not disqualify him in the eyes of most Republican voters—though Alabamans rejected Roy Moore in a Senate race this month, after he had been accused of harassment and assault by several women, including one who was 14 at the time. And yet among some people Mr Trump’s victory inspired a longing for powerful, abusive men to face a reckoning. The Women’s March against his inauguration was the biggest day of protest in America’s history.

The dam broke in October, with accusations of harassment and assault against Harvey Weinstein, a film producer. Since then dozens of prominent men in show business, journalism and politics have been accused of sexual harassment, and been sacked or stepped down. The #MeToo hashtag has already been used 4.7m times on Twitter by women (and a few men) whose harassers were not famous enough to make the news.

Both sexes have found the outpouring astonishing. Many men are amazed to learn that so many women have suffered sexual harassment. For women the surprise is that perpetrators are being punished at last.

Norms under construction

Social change often starts with a grassroots movement. It can promote new ways of thinking, or reveal injustices that had long been ignored. New behavioural rules may follow. But if these emerging norms are not embraced by big parts of the population, they will not become entrenched. And if transgressions are seen to go unremarked or unpunished, they will continue.

Progress is often halting. Until the past few years, when same-sex marriage became law in dozens of countries, gay-rights campaigners suffered a string of defeats. Progress can also be incomplete. The past half-century has seen the criminalisation of rape within marriage and tougher laws against domestic violence. However, both crimes are still common, and rarely punished. Some mass movements end in failure. America’s temperance campaigners achieved Prohibition in 1920. Just 13 years later the bars came out of hiding and were back in business.

Ms Bicchieri emphasises how exceptional people often get the process started. They may be braver than the average person, or more motivated—or have less to lose. If there are enough of them, the trend can accelerate, because each new follower makes it easier for the next.

During the 1950s the number of black students on American campuses increased by a third. Students were central to the success of the civil-rights movement as they could go on marches or stage sit-ins without being sacked. In the 1970s some battered wives, fired up by second-wave feminism, left their husbands and set up refuges, making it easier for other abused women to join them. The AIDS epidemic of the 1980s galvanised gay men who had lost loved ones to come out. The fight for treatment forged a disciplined movement that won the battle for same-sex marriage three decades later.

As a trend builds, so does public awareness. Even defeats can keep campaigners’ demands in the public eye. When civil-rights marchers were arrested and beaten, it became harder to ignore discrimination against black people. Abused women in refuges were more visible than those at home, boosting support for stricter laws against domestic violence. As friends, colleagues, uncles, aunts, brothers and sisters came out, the straight majority was confronted by the fact that gays were not freaks. The share of Americans who supported gay marriage grew from little over a quarter in 1996 to a majority in 2011.

Looking back, it can be startling to see how blind people were to injustices that were kept private by custom. Domestic violence used to be a family matter. Doctors thought it was rare, and that victims had psychological problems. The Journal of Marriage and Family, founded in 1939, had no entry for violence in its index for its first 30 years. It is now widely accepted that one of the most dangerous places for women and children is the home.

For sexual harassment, this process of general enlightenment is well under way. Each new woman who shares her story, and each perpetrator who loses his job, inspires more women to come forward and more firms to revisit allegations they had long ignored.

Once a new idea is in the air, it can catch on, or it can fade away. If it is to survive, society needs to form a new “normative expectation”, a shared belief about how to behave. This is a delicate moment.

Shining a light on bad behaviour may have unintended consequences. Campaigners against date rape on university campuses, for example, must take care that revealing how many women have been victims does not lead some men to conclude that, if date rape is really so common, it cannot be particularly serious. Alternatively, bystanders may conclude the problem is being exaggerated or exploited to make a political point—as a Democratic ploy to harm Mr Trump, for example. It is worth explaining that a few prolific men can leave many victims.

Or the new way of thinking may spread within certain groups, but fail to convince the public at large. The emerging norm will then be enforced patchily, if at all. Few people will intervene to stop an act they think should not merit sanction. They may even go as far as helping transgressors to evade what they see as an unfair penalty. If a law is not widely agreed to be just—harsh punishment for the possession of marijuana for personal use, say—then the authorities often turn a blind eye.

The main reason for the repeal of Prohibition was that the temperance movement never managed to persuade most Americans that drinking alcohol was truly wicked. Among the world’s most widely flouted laws are those against speeding. Many drivers see little harm in it: some will even flash their headlights to warn others of speed traps ahead. In most countries where female genital mutilation (FGM) is common, it is formally banned. But prosecutions are rare.

At the moment, the most egregious sexual harassers are no doubt fearful. But history suggests that, if large numbers of men feel that they are being unjustly lumped in with rapists, they will be unlikely to step in when a woman is being pestered. And if men think that the rules of workplace behaviour are being redrawn too tightly, they will not back her up if she complains. Minor transgressions will thus remain common—and, when the storm has died down, major ones could pick up again. “Women, I’m begging you: think this through,” writes Claire Berlinski in American Interest, a magazine. “We now have, in effect, a crime that comes with a swift and draconian penalty, but no proper definition.” A golden opportunity to tackle harassment could be squandered.

Some women also fret that among the #MeToo stories are more than a few that stray too close to framing women as weak, helpless and lacking in sexual agency. In the Cut, an online women’s magazine, Rebecca Traister warns of a backlash: “all it will take is one particularly lame allegation…to turn the tide from deep umbrage on behalf of women to pity for the poor, bullied men.” At least two politicians accused of sexual impropriety, Carl Sargeant from Wales and Dan Johnson from Kentucky, have killed themselves.

Few men have yet dared to go public with their reservations. But plenty will say in private that some of the #MeToo stories seem to stray into revisionism. Without the full story it is hard to judge. But a man who reads that another has been sacked for putting a hand on a woman’s knee may protest, not without reason, that men have always been expected to take the sexual initiative and are now supposed to be mind-readers, too. “Affirmative consent”—the notion gaining currency on campus that explicit verbal agreement should be sought at every stage as a relationship unfolds—may be a fine idea. But any romantic film more than a few years old will confirm that it is a new and untested one.

Perhaps it is simply too bad if men feel discombobulated. Perhaps it is now women’s turn to say how the sexes should interact. But, as Prohibition shows, a new norm has little chance of becoming entrenched if it is rejected by half the population. And in the fight against sexual harassment, women need their male colleagues as allies. Ordinary people are essential for enforcing social norms—and indeed laws. Neither HR staff nor the police can be everywhere.

Today, men and women often disagree about what should count as sexual harassment. Almost everyone, male or female, accepts that sexual favours cannot be made a condition for a job or a promotion. Big majorities see unwanted touching as wrong. But the sexes differ over ogling a woman or making unwelcome sexualised remarks. Young men’s attitudes are more similar to women’s than older men’s are, but the gap persists.

Sometimes, a consensus can be forged by calling on deeper, long-held social norms. Ms Bicchieri cites campaigns against FGM that have described uncut girls as pure, intact and as God made them. From that viewpoint, FGM violates fundamental Islamic values. Campaigners against domestic violence in Latin America sometimes try to get machista attitudes to work for them by saying that a “real man” is the family protector and would therefore never hit his wife or child. Ms Bicchieri speculates that older men—the group most likely to minimise sexual harassment and least likely to be won over by feminist arguments—might be brought round by the notion that upsetting women is not the behaviour of a gentleman.

Ultimately, though, a new norm will only be adopted if it is widely agreed to be important. For sexual harassment, that means demonstrating the harm it does. Hundreds of studies have looked at how marriage, motherhood and education affect women’s careers and earnings, but the damage from harassment has largely been overlooked. The few studies that exist suggest it is an underappreciated reason why women are paid and promoted less than men, and even why so few women work in traditionally male fields.

In a paper published in May in Gender & Society, an academic journal, Heather McLaughlin, Christopher Uggen and Amy Blackstone analysed responses from participants in the Youth Development Study, which has followed a cohort in St Paul, Minnesota, since 1988. In 2002-03, when participants were aged 28-30, 11% of the women who had jobs said they had suffered sexual harassment at work in the previous year. Two years later, they earned less than the other women, and were more likely to be in financial distress. More than half had changed jobs. For those who had been harassed repeatedly or experienced unwanted touching, the figure was 79%.

In follow-up interviews the researchers heard how some of those women had abandoned careers they had spent years training for, or left jobs despite having no other employment. Some felt that this was the only way to escape. Others felt betrayed by their employers’ and their colleagues’ feeble responses. They saw HR staff as more interested in hushing things up than stopping the harassment.

Some of the interviewees said their employer had been unwilling to confront a man who was seen as a star performer. And many of those brought down by the recent allegations had long been treated as untouchable because they brought in a lot of business. But turning a blind eye to sexual harassment is now risky for firms. Mr Weinstein’s star was already fading before the accusations against him were made public. Since then, the Weinstein Company, which he founded with his brother, has had to seek a buyer.

Firms that are lax about sexual harassment are waking up to the risk of expensive lawsuits. Recent research into “toxic” workers, whose behaviour harms a company’s assets or other employees, suggests that employers’ self-interest should have caused them to take harassment more seriously all along. In a paper published in 2015 in the Harvard Business Review, Michael Housman of Cornerstone OnDemand, a consultancy, and Dylan Minor of Northwestern University analysed data on 50,000 workers in 11 firms. They found that toxic workers were much more productive than the average—presumably because equally unpleasant people who were less productive had been let go. But that was more than outweighed by the damage they did to their colleagues’ productivity and by job churn, as people resigned to get away from them. A firm does better to get rid of a toxic worker, they concluded, than to replace an average one by someone in the most productive 1%.

The final step in creating a durable social norm, says Ms Bicchieri, is when normative expectations become empirical ones—that is, when everyone can see that the new rules are sticking. For sexual harassment, this means that women must be able to continue speaking out and perpetrators must continue to be punished. It also means that men who might have been perpetrators continue to think twice and decide against it.

Duncan Green of Oxfam, the author of “How Change Happens”, makes a distinction between the self-deluded and the bullies. The self-deluded may be put off by their newfound understanding of how strongly women feel about unwanted sexual attentions. But the bullies are unlikely to care, and may even enjoy the thought of making women miserable. Detailed accounts of some of the allegations aired in recent weeks suggest that humiliating women was part of the point.

A bigger stick

For a bully to stop, says Mr Green, he needs to be afraid of someone. As more women rise to senior positions, more of them will have the power to face the harassers down. Until then, the job will often fall to other men, as both managers and bystanders. That is the biggest reason women need men with them in a united front.