Doubts about a Harvard professor’s landmark finding

By Daisy Grewal

Scientific American, November 29, 2016 —

Credit: Getty Images


In 2007 the Harvard professor Robert Putnam published a paper that appeared to challenge the benefits of living in a racially diverse society. Putnam’s study, which used a large, nationally representative sample of nearly 30,000 Americans, found that people living in more diverse areas reported lower levels of trust in their neighbors. They also reported less interest in voting, volunteering, and giving to charity. In other words, greater diversity seemed to be linked to both feelings and behaviors that threaten a sense of community. The finding was alarming to many people, including Putnam himself, because the U.S. continues to grow in racial and ethnic diversity with each passing decade.

Putnam’s research was widely cited, both within academia and by the media, as a counterargument to popular notions about the benefits of diversity. His paper was even cited in a brief filed for the high-profile case, Fischer v. University Texas, concerning the legal fairness of affirmative action processes at public universities. Abigail Fisher, a white woman, was denied admission to the University of Texas at Austin in 2008 and filed suit, alleging racial discrimination on the part of the university due to affirmative action. Putnam filed a brief of his own, objecting to the use of research findings in making a case against diversity policies. But what if the conclusions stemming from Putnam’s research were actually wrong to begin with?

Sociologists Maria Abascal, of Princeton University, and Delia Baldassari, of New York University, published a paper late last year which refutes Putnam’s conclusions.

After reanalyzing the same dataset used by Putnam, Abascal and Baldassari asserted that when it comes to distrust and diversity, most of the distrust is expressed by Whites who feel uncomfortable living amongst racial minorities.

In other words, greater distrust may stem from prejudice rather than from diversity per se.

Therefore, Putnam’s conclusion that racial diversity leads to less altruism and cooperation amongst neighbors was incorrect. If there is a downside to diversity, it has less to do with the behavior of racial minorities and more to do with how Whites feel when living amongst non-Whites.

To understand why Abascal and Baldassari came to such different conclusions than Putnam, one has to start with understanding how researchers have traditionally defined and measured the “diversity” of a community. Scholars, including Putnam, have measured diversity through a concept called the heterogeneity index, which tells you what proportion of a community is made up of members of different groups. Using the index, a community made up of 80% Whites and 20% Blacks would be considered equally “diverse” as one made up of 20% Whites and 80% Blacks.
This is a problematic assumption. Think about the example of a neighborhood that’s 80% White and 20% Black. If I am a White person living in that neighborhood, I’m much more likely to interact with people who are the same race as me than if I were living in a neighborhood that is 80% Black. If I’m Black living in the same neighborhood, the opposite is likely to be true. Abascal and Baldassari found that Whites living with more racial minorities report the highest levels of distrust.

They also found another factor which skewed Putnam’s results. The survey that Putnam drew his findings from is called the Social Capital Community Benchmark Survey. It was administered in 2000 to a nationally representative sample across 41 U.S. communities. The survey had five questions about trust. One question reads, “Generally speaking, would you say that most people can be trusted or that you can’t be too careful in dealing with people?” and respondents are asked to answer on a three-point scale expressing high, moderate, or low levels of trust. Past research has shown that Blacks and Hispanics, on average, report less trusting attitudes than do Whites. Without controlling for this, neighborhoods with more Blacks and Hispanics will appear to have lower “trust,” but for reasons having nothing to do with the degree of diversity.

There is a third factor to consider, the authors argue. In the U.S., heterogeneous communities tend to be undergoing demographic change, either due to white flight or gentrification. Sadly, it’s rare to see well-established and stable racially diverse communities. Therefore, it may be the instability of diverse communities, rather than diversity itself, that erodes trust. Greater neighborhood instability has been linked to many other negative outcomes such as more substance abuse, child abuse, infant mortality, and crime.

Abscal and Baldassari’s findings lead to uncomfortable conclusions about the role that racial diversity plays in our society. When non-Whites move into predominantly White communities, it has the potential to unmask racism and prejudice. Perhaps one of the reasons that this idea has been rarely discussed, both by academics and by the public, is because it is such a difficult topic to address. It illuminates the gap between how we might want to see things versus how they actually are. Past community research on racially mixed neighborhoods shows how Whites often appreciate and esteem diversity in the abstract while geographically distancing themselves from non-Whites. Efforts to celebrate diversity as an ideal will do little to solve the practical challenges of living in an increasingly multicultural society. Instead, we will need to first acknowledge and discuss that for some of us, living alongside people who are different is not as desirable as we might like to think.


Daisy Grewal holds a BA in psychology from UCLA and a PhD in social psychology from Yale University. She currently works at Stanford University as an applied researcher.