Diversity’s Elusive Number: Campuses Strive to Achieve ‘Critical Mass’

Is there an optimal number of minority students on a college campus? At what point are diversity’s educational benefits broadly realized, and is there a threshold at which students in underrepresented racial groups feel welcome?

Those questions are at the center of a series of affirmative-action cases at the Supreme Court and recent student demonstrations for improved racial climates.

Since its decision in Grutter v. Bollinger, in 2003, the Supreme Court has framed the number as a “critical mass.” About one-third of the student-activist groups that have issued demands on approximately 70 campuses nationwide have sought to increase the share of black students to help them feel less isolated. Protesters at Washington University in St. Louis, for example, have advocated for the share of black and Latino students each to increase to 10 percent of enrollment. Students at Michigan State University want the number of underrepresented students from urban areas to triple by 2017-18.

So, what’s the right number?

Education researchers have shied away from articulating one. Critical mass, the American Educational Research Association argued, “should be examined dynamically, and is contingent upon several factors beyond simple numerical targets.” Factors like a college’s racial climate, history, and institutional practices ought to be weighed on a case-by-case basis, the association wrote in its brief to the Supreme Court in Abigail Noel Fisher v. University of Texas at Austin (No. 14-981), in support of Texas. The case is being argued on Wednesday.

Colleges face a Catch-22, says Liliana M. Garces, an assistant professor of education at Pennsylvania State University, and a researcher whose work is widely cited in the association’s brief. When colleges fix on a number for critical mass, she has written, “it becomes a quota, but if the concept is not a number, then the concept is too amorphous.”

Numbers are then both central to concerns about diversity — and a distraction. “I’m not saying numbers don’t matter,” Ms. Garces said in an interview. “Obviously, they do matter, but not when they’re separate from the context in which students find themselves.”

One potentially useful way to think about numbers is suggested by research by the Higher Education Research Institute at the University of California at Los Angeles.

Since 2010, researchers there have administered the Diverse Learning Environments Survey, which asks students for their views on their campus’s climate on issues of race, gender, religion, and sexual orientation, among others.

As the researchers sifted through the data to gauge the relationship between minority representation and campus climate, they had in the back of their minds the work of Rosabeth M. Kanter, a professor of business administration at the Harvard Business School. She studied the experiences of women in corporations in the 1970s, finding that when their ranks reached a certain threshold — about 35 percent — their presence started to change their organizations’ culture, norms, and values.

UCLA’s researchers ran their numbers and observed a threshold similar to the one Ms. Kanter found. Black, Hispanic, and Native American students were less likely to say they had personally been the object of discriminatory verbal comments, had seen offensive images, and had felt excluded from events and activities when their combined numbers on a campus were higher than 35 percent. As the rates of hostile interactions dropped, their sense of belonging on a campus rose, the researchers found. And a sense of belonging tends to predict retention and persistence.

“Discrimination starts to diminish as the numbers start to increase,” said Sylvia Hurtado, a professor of education at UCLA who leads the institute’s Diverse Learning Environments Survey. Her findings are based on the responses of nearly 8,900 minority students at 58 four-year colleges from 2010 to 2015.

When more diverse groups of students are on a campus, she said, it tends to disrupt stereotypes and reduce microaggressions. It affects the perceptions of white students, too. “They see there’s variability within these groups,” Ms. Hurtado said. Other benefits include greater tolerance of difference and increases in critical-thinking skills, especially among white students.

The findings might be an artifact of having a relatively small number of campuses in the survey, Ms. Hurtado said. To have a large enough sample of minority students to make observations, the researchers had to combine black, Hispanic, and Native American groups (Asian-Americans were excluded from the analysis, researchers said, because they are not underrepresented in higher education).

But combining categories also has a certain logic, Ms. Hurtado said, because it encourages a broad conception of diversity. “To have a more mutually beneficial learning environment,” she said, “it helps to have a variety of groups.”

Ms. Hurtado stopped short of identifying the 35-percent threshold as critical mass, however. That term describes a broader phenomenon: a campus’s culture, the quality and frequency of meaningful interactions there, faculty demographics, and an institution’s policies.

“I don’t want it to turn into a magic number,” she said. “You can have a bunch of diverse people in a room, but if they don’t interact, you’re not going to get the benefits of diversity.”

Risks and Benefits

Affixing numerical targets to diversity goals can risk undermining those efforts, said several scholars. Administrators might be tempted to declare victory after hitting enrollment numbers but then neglect to offer resources that help minority students succeed once they arrive.

Enrolling more minority students is good, but only if colleges take concrete steps like establishing multicultural-affairs offices and other resources that might help them persist and graduate, said Shaun R. Harper, a professor in the Graduate School of Education and executive director of the Center for the Study of Race and Equity in Education at the University of Pennsylvania.

“College and university administrators,” he said, “are notorious for presuming that if we could just get a bunch of students from different groups in a residence hall, they’ll magically interact with each other in meaningful ways.”

An even bigger challenge, Mr. Harper said, is increasing the number of minority faculty members and administrators. Without adequate racial representation in the ranks of the professoriate and leadership, he added, the human infrastructure of institutions will continue to feel overwhelmingly white, even on campuses with many black, Hispanic, and Native American students.

Thinking about diversity beyond a count of single groups but as a collection of different ones has its uses. Robust groups of different students can deepen their understanding of one another and build solidarity, Mr. Harper said. But important distinctions can also get papered over.

Mr. Harper’s research has found that students tend to report varying levels of satisfaction with college, based on their race. White students are the most satisfied. Hispanic and Asian-American students often acknowledge that they experienced discrimination but still feel somewhat satisfied. Black students are the most dissatisfied, he said, because they have a longer history with their institutions than other minority groups do, and it’s often filled with disappointment and hurt.

Ms. Hurtado’s research found similar distinctions among minority groups. As campuses became more diverse, she found, the rate at which Hispanic students reported incidents of bias and discrimination decreased. The pattern was linear.

Black students, however, followed a different path. The rate of black students’ reports of such incidents increased when their campuses had “moderate” levels of underrepresented minorities, defined as 21 to 35 percent, even when compared with institutions with the lowest rates of diversity.

Once minorities accounted for more than 35 percent of the student body, the rates of reports dropped back down, mirroring the broader pattern. When black students are isolated, as they would be on campuses with low levels of diversity, they may be more reluctant to report their experiences, several scholars said.

The Big Picture

While 35 percent may not be the critical mass for every campus, it is a bar that few colleges reach.

Campuses whose share of underrepresented students fails to crack 20 percent include some of the highest-profile sites of conflict in recent months: Yale and Princeton Universities, the Universities of Missouri and Oklahoma, and Claremont McKenna College. Among the approximately 70 campuses with student demands cataloged on the website thedemands.org, all but five fall below the 35-percent threshold.

The number of Title IV-compliant, four-year, degree-granting public and nonprofit private colleges where at least 35 percent of first-time, full-time, degree-seeking undergraduates are black, Hispanic, or Native American is just 374, about 19 percent of the total number of such institutions. More than a third of those diverse institutions are designated as historically black or tribal, or have Hispanic enrollments of 80 percent or more, according to federal data.

Increasing numbers of students of any kind should prompt colleges to change to meet the students’ needs, said Deborah A. Santiago, chief operating officer and vice president for policy at Excelencia in Education, which promotes efforts to help Hispanic students succeed in college. That holds true when the students represent races that have historically not enrolled in higher education, as is happening now, just as it did in the past when women, veterans, or commuters flooded campuses.

At a certain point, Ms. Santiago said, the changing composition of a campus’s student body will become so altered that a college must evolve, too. When? “It could be 15 percent,” she said. “It could be 40 percent.”

But demographics alone won’t embed new cultures on campuses or lead to student success, she added. Many Hispanic students, for example, are the first in their families to attend college. They often need academic advising that is more active and intrusive than it is for white students, she said.

What ultimately matters, said Ms. Santiago, is that colleges act thoughtfully and intentionally.

“Institutions that are oblivious,” she said, “might be missing the boat.”

Ariana Giorgi contributed to this article.

Dan Berrett writes about teaching, learning, the curriculum, and educational quality. Follow him on Twitter @danberrett, or write to him at dan.berrett@chronicle.com.