According to recent research, ethnoracial diversity negatively affects trust and social capital. This article challenges the current conception and measurement of "diversity" and invites scholars to rethink "so-cial capital" in complex societies. It reproduces the analysis of Putnam and shows that the association between diversity and self-reported trust is a compositional artifact attributable to residential sorting: non-whites report lower trust and are overrepresented in heterogeneous communities. The association between diversity and trust is better explained by differences between communities and their residents in terms of race/ethnicity, residential stability, and economic conditions; these classic indicators of inequality, not diversity, strongly and consistently predict self-reported trust. Diversity indexes also obscure the distinction between in-group and out-group contact. For whites, heterogeneity means more out-group neighbors; for nonwhites, heterogeneity means more in-group neighbors. Therefore, separate analyses were conducted by ethnoracial groups. Only for whites does living among out-group members--not in diverse communities per se--negatively predict trust.

Using field experiments, scholars can identify causal effects via randomization while studying people and groups in their naturally occurring contexts. In light of renewed interest in field experimental methods, this review covers a wide range of field experiments from across the social sciences, with an eye to those that adopt virtuous practices, including unobtrusive measurement, naturalistic interventions, attention to realistic outcomes and consequential behaviors, and application to diverse samples and settings. The review covers four broad research areas of substantive and policy interest: first, randomized controlled trials, with a focus on policy interventions in economic development, poverty reduction, and education; second, experiments on the role that norms, motivations, and incentives play in shaping behavior; third, experiments on political mobilization, social influence, and institutional effects; and fourth, experiments on prejudice and discrimination. We discuss methodological issues concerning generalizability and scalability as well as ethical issues related to field experimental methods. We conclude by arguing that field experiments are well equipped to advance the kind of middle-range theorizing that sociologists value.

How do members of dominant groups, like White people in the United States, react when their privileged social status is threatened, for example, by the prospect of numeric decline? Prior studies identify two sets of reactions: (1) White people identify more strongly with ingroup members, and (2) they withhold material and symbolic resources from outgroup members. This study explores another possibility: White people may alter the boundary around Whiteness by redefining the criteria for membership. I use an original survey experiment to examine how demographic threat affects how White people in the United States classify people who are ambiguously White, and specifically people who are ambiguously White or Latino. The results reveal that White people are less—not more—likely to classify people who are ambiguously White or Latino as “White” under threat. The results contribute to a growing literature on the racial classification of multiracial and racially ambiguous people that has previously ignored ambiguity around the Latino category. They also speak to an active debate about demographic projections and the classification decisions on which they rest.

Previous studies reach contradictory conclusions regarding the relationship between residential concentration and naturalization. This paper tackles the impasse by exploring the pathways through which immigrant communities influence individual naturalization. Specifically, this study examines naturalization among Latino immigrants using the 2006 Latino National Survey linked to county data. Multilevel model results indicate that the county concentration of naturalized co‐ethnics positively predicts individual naturalization, and this relationship operates through two channels: information dissemination and perceived belonging. Regarding the latter, Latino immigrants who live among naturalized co‐ethnics identify more strongly as “American,” and strength of American identification mediates nearly one‐half of the relationship between concentration and naturalization.

How will Hispanic population growth affect black-white relations in the United States? Research on intergroup relations operates within a two-group paradigm, furnishing few insights into multi-group contexts. This study is based on an original experiment that combines behavioral game and survey methods to evaluate the impact of perceived Hispanic growth on attitudes and behavior. Results reveal opposite reactions among blacks and whites. Whites in the baseline condition contribute comparable amounts to black and white recipients in a dictator game, whereas whites who first read about Hispanic growth contribute more to white recipients than to black ones. By contrast, blacks in the baseline condition contribute more to black recipients than to white ones, whereas blacks who first read about Hispanic growth contribute comparable amounts to black and white recipients. Patterns of identification mirror patterns of contributions: whites exposed to Hispanic growth identify relatively more strongly with their racial group than with their national group, whereas blacks exposed to Hispanic growth identify relatively more strongly with their national group than with their racial group. Together, these results suggest that people respond to the growth of a third group by prioritizing the most privileged identity to which they can plausibly lay claim and which also excludes the growing group.

Immigration and globalization have spurred interest in the effects of ethnic diversity in Western societies. Most scholars focus on whether diversity undermines trust, social capital, and collective goods provision. However, the type of prosociality that helps heterogeneous societies function is different from the in-group solidarity that glues homogeneous communities together. Social cohesion in multiethnic societies depends on whether prosocial behavior extends beyond close-knit networks and in-group boundaries. We identify two features of modern societies—social differentiation and economic interdependence—that can set the stage for constructive interactions with dissimilar others. Whether societal adaptations to diversity lead toward integration or division depends on the positions occupied by minorities and immigrants in the social structure and economic system, along with the institutional arrangements that determine their political inclusion.

The term “diversity,” although widely used, can mean different things. Diversity can refer to heterogeneity, i.e., the distribution of people across groups, or to the representation of specific minority groups. We use a conjoint experiment with a race-balanced, national sample to uncover which properties, heterogeneity or minority representation, Americans use to evaluate the extent of racial diversity a neighborhood and whether this assessment varies by participants’ race. We show that perceived diversity is strongly associated with heterogeneity. This association is stronger for Whites than for Blacks, Latinos, or Asians. In addition, Blacks, Latinos, and Asians view neighborhoods where their own group is largest as more diverse. Whites vary in their tendency to associate diversity with representation, and Whites who report conservative stances on diversity-related policy issues view predominately White neighborhoods as more diverse than predominately Black neighborhoods. People can agree that diversity is desirable while disagreeing on what makes a community diverse.

Scholarship on the consequences of racial/ethnic diversity often claims that diversity undermines trust, participation and cooperation. This work has been criticized for its inability to discern the causal effects of diversity. We draw attention to a more elementary issue: most studies are unable to interpret associations between their outcomes of interest and diversity, as these may be due to associations with non-White or immigrant shares. We make the practical and theoretical case for preserving the distinction between diversity—i.e., mixture—and non-White or immigrant shares—e.g., percentage Black or percentage foreign-born—, and we warn scholars about the dangers of using language and measures associated with diversity, especially in contexts, like North America and Europe, where diversity strongly overlaps with non-White or immigrant shares. On a practical front, the policy recommendations that follow from the claim “greater diversity is associated with less prosociality” are different from those that follow from the claim “greater non-White share is associated with less prosociality among Whites.” On a theoretical front, most studies of diversity rely on theories that are predicated on ingroup/outgroup shares—most commonly intergroup conflict/threat theory—rather than on diversity; the predictions implied by popular theories, however, contradict those implied by claims about diversity. Importantly, two empirical obstacles undermine our capacity to disentangle associations with diversity from associations with non-White or immigrant shares. The first stems from the underrepresentation of predominately non-White (or predominately immigrant) communities in the real world. The second concerns our ability to infer that individual attitudes and behavior are correlated with diversity from correlations between macro-level outcomes and diversity. Finally, we spell out the kinds of data required to draw empirically sound conclusions about associations between diversity and social outcomes. With an appendix by Daniel Lacker.