No great universities exist in the world without a deep institutional commitment to academic freedom, free inquiry, and free expression. For the past 60 years, American research universities have been vigilant against external and internal attempts to limit or destroy these values. The First Amendment scholar Geoffrey Stone has noted that free expression, in one form or another, has been continually under attack on campuses for the past 100 years. Today, these core university values are being questioned again, but from a new source: the students who are being educated at them.

What explains this recent outcry against free expression on campus? Multiple possible explanations exist, of course, including the hypothesis that parents have coddled a generation of youngsters to the point where students feel that they should not be exposed to anything harmful to their psyches or beliefs. Whether or not these psychological narratives are valid, there are, I believe, additional cultural, institutional, and societal explanations for what is going on. And the overarching theme is that today’s youngsters, beginning in preschool, are responding to living in a contrived culture of fear and distrust.

There’s hardly consensus among students on the forms or appropriateness of these restrictions on speech. Today, nearly half of a random sample of roughly 3,000 college students surveyed by Gallup earlier this year are supportive of restrictions on certain forms of free speech on campus, and 69 percent support disciplinary action against either students or faculty members who use intentionally offensive language or commit “microagressions”—speech they deem racist, sexist, or homophobic. According to a free-speech survey conducted by Yale last year, of those who knew what trigger warnings are, 63 percent would favor their professors using them—by attaching advisories to the books on their reading lists that might offend or disrespect some students, for example—while only 23 percent would oppose. Counterintuitively, liberal students are more likely than conservative students to say the First Amendment is outdated.

Consider a few recent cases: Brown University, Johns Hopkins University, Williams College, and Haverford College, among others schools, withdrew speaking invitations, including those for commencement addresses, because students objected to the views or political ideology of the invited speaker. Brandeis University began to monitor the class of a professor who had explained that Mexican immigrants to the United States are sometime called “wetbacks,” a comment about the history of a derogatory term that outraged some Mexican American students. Black students at Princeton University protested against the “racial climate on campus” and demanded that Woodrow Wilson’s name be removed from its school of Public and International Affairs. The chilling effect of these kind of restrictions on speech were not lost in 1947 on Robert Hutchins, the president of the University of Chicago, who opined during the McCarthy period: “The question is not how many professors have been fired for their beliefs, but how many think they might be.”

Born in the mid-1990s, seniors in my Columbia University undergraduate seminars today likely have not experienced major national threats, except for their vague memories of the 9/11 terrorist attacks. Yet these “millennials” might better be labeled “children of war and fear.” During their politically conscious lifetime, they have known only a United States immersed in protracted wars against real and so-called terrorists, a place where fear itself influences their attitudes toward other civil liberties. Students are asked to pit freedom of expression or privacy against personal security. During times when elected officials have exploited the public’s fear of terrorism for political gain, students seem more willing to trade civil liberties for a sense of security.

Since the 9/11 tragedy, the use of fear is still pervasive in the United States. Indeed, the distortion of fear pervades today’s students’ thinking—they tend to overestimate, for example, the probability of a terrorist attack affecting them. When this fear is combined with the rapid expansion of social media and the prevalence of government surveillance, students often dismiss concepts like “privacy” as old-fashioned values that are irrelevant to them, In fact, my experience at Columbia suggests that many students believe that the very idea of privacy is obsolete; most of my students don’t seem to mind this loss when it’s weighed against uncovering potential terrorists.

Add to this apprehension the fears that so many students of color experienced before college—a rational fear of the police, of racial stereotypes, of continual exposure to epithets and prejudice—and it is no wonder that they seek safe havens. They may have expected to find this safe haven in college, but instead they find prejudice, stereotyping, slurs, and phobic statements on the campuses as well. Additionally, many of these students employ the classification of “the insider.” Believing that “outsiders” cannot possibly understand the situation that faces these groups of offended individuals, by virtual of race, gender, ethnicity, or some other category, the students often dismiss the views of their professors and administrators who can’t “get it” because they are not part of the oppressed group.

Many of the young adults at highly selective colleges and universities have been forced to follow a straight and narrow path, never deviating from it because of a passion unrelated to school work, and have not been allowed, therefore, to live what many would consider a normal childhood—to play, to learn by doing, to challenge their teachers, to make mistakes. Their families and their network of friends and social peers have placed extreme pressure on them to achieve, or win in a zero-sum game with their own friends. While it’s difficult to assess the cases, and while myriad factors likely contribute to the poor mental health among college students, in 2015 roughly 18 percent of undergraduates reported being diagnosed or treated for anxiety in the past year, according to the American College Health Association’s 2015 annual survey; the rate was 15 percent for depression. Many are taking anti-depressants and anti-anxiety medication upon entry into college.

But there is a different, though equally important, reason many students today are willing to suppress free expression on campus. And the fault largely lies at the feet of many of the country’s academic leaders. Students and their families have been increasingly treated as “customers.” Presidents of colleges and universities have been too reluctant to “offend” their customers, which may help explain why they so often yield to wrong-headed demands by students. Courage at universities is, unfortunately, a rare commodity—and it’s particularly rare among leaders of institutions pressured by students to act in a politically correct way.

It seems that the vast majority of presidents and provosts of the finest U.S. universities have not seized this moment of concern voiced by students as a teaching moment—a moment to instruct and discuss with students what college is about. Too many academic leaders are obsessed with the security of their own jobs and their desire to protect the reputation of their institution, and too few are sufficiently interested in making statements that may offend students but that show them why they are at these colleges—and why free expression is a core and enabling value of any higher-learning institution that considers itself of the first rank. Of course, there are strong academic leaders who do encourage open discussions of issues raised by students while also speaking out against restrictions on campus speech, against speech codes, safe-space psychology, and micro-aggressions. But they are too few and far between.

Students want to be protected against slurs, epithets, and different opinions from their own—protected from challenges to their prior beliefs and presuppositions. They fear not being respected because of a status that they occupy. But that is not what college is about. While some educators and policymakers see college primarily as a place where students develop skills for high-demand jobs, the goal of a college education is for students to learn to think independently and skeptically and to learn how to make and defend their point of view. It is not to suppress ideas that they find opprobrious. Yet students are willing to trade off free expression for greater inclusion and the suppression of books or speech that offend—even if this means that many topics of importance to their development never are openly discussed.

Of all of America’s great universities, the University of Chicago seems to have come the closest historically to getting this right. The school’s well-known 1967 Kalven Committee report was, I believe, correct when it stated: “The mission of the university is the discovery, improvement, and dissemination of knowledge. Its domain and scrutiny includes all aspects and all values of society. A university faithful to its mission will provide enduring challenges to social values, policies, practices, and institutions. By design and by effect, it is the institution which creates discontent with the existing social arrangements and proposes new ones. In brief, a good university, like Socrates, will be upsetting.” Almost 50 years later, at the request of its President Robert Zimmer, The University of Chicago again articulated its position on “freedom of expression.” The short document quotes the historian and former Chicago president, Hanna Holborn Gray: “Education should not be intended to make people comfortable, it is made to make them think. Universities should be expected to provide the conditions within which hard thought, and therefore strong disagreement, independent judgment, and the questioning of stubborn assumptions, can flourish in an environment of the greatest freedom.” “In a word,” the report goes on, “the University’s fundamental commitment is to the principle that debate or deliberation may not be suppressed because the ideas put forth are thought by some or even by most members of the University community to be offensive, unwise, immoral, or wrong-headed.” Yet students may be signaling that their commitment to “community” values may take precedence over this core value that many administrators have seen as essential for truly great institutions of learning.

A physically safe environment is an absolutely necessary condition for heated debate over ideas. The university cannot tolerate violations of personal space, physical threats, sustained public interruptions of speakers, or verbal epithets directed toward specific students; that lies beyond the boundaries of academic freedom. That doesn’t mean, however, that a college or university should introduce policies that will curtail or chill debate, that adhere to the politically correct beliefs of the moment, or that let their leaders off the hook through capitulation to “demands” that stifle discourse and conversations about what a university education aims to produce.