Interventions to Improve Intergroup Relations: What Works, What Shows Promise, and What this Means for Civil Politics


Interventions to Improve Intergroup Relations:

What Works, What Shows Promise, and What this Means for Civil Politics


Jesse Graham

(research summaries by Charlie Ebersole, Ravi Iyer, Julia Loup, Matt Motyl, Laura Ramer, Ariana Shives, Mike Nettis-Benstock, Andrew Pilecki, & Li Zhang)

1. Introduction


At, we are focused on ways to get ideological opponents to stop hating each other so much and start working together, for a more productive democracy. This, it turns out, is really really hard to do. Surveying the scientific literature for interventions that might get us closer to this goal, we found that most (but not necessarily all) of the roadblocks to partisan intergroup cooperation are the same as the roadblocks to all forms of intergroup cooperation – not just Democrats and Republicans, but Palestinians and Israelis, Red Sox fans and Yankees fans, or even irrelevant group divisions created for behavioral experiments in the lab. With this in mind, we have been collecting and summarizing research on interventions designed to improve intergroup relations – regardless of what forms these groups, interventions, or relations take. In this annotated bibliography (linking to both the original papers and the more accessible research summaries posted on, I will summarize what has been shown to robustly work, and what hasn’t been researched as thoroughly but shows promise for improving intergroup relations, and what we see as opportunities for improvement on our collective understanding of how moral divisions can be transcended. In my opinion, the most empirically-supported methods for improving intergroup relations both have their origins in classic psychology: 1. Promoting cross-group interpersonal interactions, and 2. Groups being faced with superordinate goals requiring intergroup cooperation. In addition, reducing moral certainty shows great promise for reducing extremism in ideological partisanship and other intergroup conflicts, as does emphasizing shared humanity and reducing zero-sum perceptions of intergroup contexts. We hope this summary can be of value for academics and non-academics alike (possibly also improving the relations between these two groups who so rarely talk to each other!). This review is a work in progress, and we will be adding to it continually as we summarize more findings and expand our intervention categories in 2015.


1.1. Annotated Bibliography: Review Papers on Intergroup Relations and Intergroup Bias


Brewer, M. B., & Kramer, R. M. (1985). The psychology of intergroup attitudes and behavior. Annual Review of Psychology36, 219-243.


Brown, R., & Hewstone, M. (2005). An integrative theory of intergroup contact. Advances in Experimental Social Psychology, 37, 255–343.


Hewstone, M., Rubin, M., & Willis, H. (2002). Intergroup bias. Annual Review of Psychology53, 575-604.


Mackie, D. M., & Smith, E. R. (1998). Intergroup relations: insights from a theoretically integrative approach. Psychological Review105, 499-529.


Motyl, M. (in press). Liberals and conservatives are (geographically) dividing. In P. Valdesolo  & J. Graham (Eds.), Bridging Ideological Divides: Claremont Series in Applied Social Psychology. New York: Wiley-Blackwell.


Tropp, L. R., & Mallett, R. K., Eds. (2011). Moving Beyond Prejudice Reduction: Pathways to Positive Intergroup Relations. New York: APA Books. – academic volume on improving intergroup relations, with chapters by different scholars on topics like expectations and inclusion in cross-group interactions, and several applications to postconflict reconciliation in different parts of the world.



2. What Works: Intervention Recommendations


2.1. Improve Personal Relationships 


The contact hypothesis (also known as Intergroup Contact Theory) is one of the oldest and most widely-discussed ideas in social psychology. The idea is that interpersonal contacts between ingroup and outgroup members are a powerful (and some would argue necessary) means by which to reduce intergroup prejudice. This idea has been supported by decades of research, from quite minimal cross-group communications to experimentally-induced cross-group friendships. Cross-group personal relationships have also been improved by interventions focused on perspective-taking and empathizing with members of the outgroup. Because the very thought of intergroup contact often causes anxiety and stress due to fear of rejection, self-affirmation interventions have been shown to improve and encourage cross-group relationships as well, by minimizing this anticipatory anxiety.


2.1.1. Annotated Bibliography: Using Personal Relationships to Improve Intergroup Relations


Allport, G. W. (1954). The Nature of Prejudice. Cambridge, MA: Perseus Books. – one of the classic texts of social psychology, this book first articulated the contact hypothesis.


Binning, K., R., Sherman, D. K., Cohen, G. L., & Heitland, K. (2010). Seeing the other side: Reducing political partisanship via self-affirmation in the 2008 presidential election. Analyses of Social Issues and Public Policy, 10, 276-292. – shows that partisans who affirmed their self-concept in the days before the 2008 US Presidential election were less partisan in their evaluation of the other party’s candidate’s debate performance, were more positive towards the opposition candidate, and more willing to consider alternative perspectives [taken from Motyl, in press].


Cameron, L., Rutland, A., Brown, R., & Douch, R. (2006).  Changing Children’s Intergroup Attitudes Toward Refugees: Testing Different Models of Extended Contact. Child Development, 77, 1208-1219. – tested the extended contact hypothesis in British 5-to-11-year-olds, with regard to their attitudes toward refugees. Three models – dual identity, common ingroup identity, and decategorization – all led to less hostile outgroup attitudes compared to control, and the effects were mediated by inclusion of the other in self (see our study summary here).


Christ, O., Hewstone, M., Tausch, N., Wagner, U., Voci, A., Hughes, J., & Cairns, E. (2010). Direct contact as a moderator of extended contact effects: Cross-sectional and longitudinal impact on outgroup attitudes, behavioral intentions, and attitude certainty. Personality & Social Psychology Bulletin, 36, 1662-1674. – provides evidence that indirect contacts with outgroup members can also help to reduce negative attitudes about the outgroup – but not as effectively as direct personal contacts can (see our study summaries here and here).


Cohen, G. L., Sherman, D. K., Bastardi, A., Hsu, L., McGoey, M., & Ross, L. (2007). Bridging the partisan divide: Self-affirmation reduces ideological closed-mindedness and inflexibility in negotiation. Journal of Personality and Social Psychology93, 415-424. – provides evidence that affirmation of one’s own integrity, combined with ideological identity salience, can reduce ideological rigidity (see our study summaries here and here).


Drolet, A. L., & Morris, M. W. (2000). Rapport in conflict resolution: Accounting for how face-to-face contact fosters mutual cooperation in mixed-motive conflicts. Journal of Experimental Social Psychology36(1), 26-50. – proposed that rapport in face-to-face interactions is crucial to increasing cooperation between the two people interacting (in this case, two people about to play a cooperative game, but this could help explain how interpersonal contact across groups improves intergroup relations).


Galinsky, A. D., & Moskowitz, G. B. (2000). Perspective-taking: decreasing stereotype expression, stereotype accessibility, and in-group favoritism. Journal of Personality and Social Psychology78(4), 708. – provides experimental evidence that perspective-taking can reduce both ingroup favoritism and stereotyping of outgroup members.


Mallett, R.K., & Wilson, T.D. (2010). Increasing positive intergroup contact. Journal of Experimental Social Psychology, 46, 382-387. – tested an experimental intervention designed to improve inter-racial friendships. Participants watched video testimonials about others’ positive interracial contacts, improving their expectations and causing them to seek out more cross-race friendships in the following weeks.


Page-Gould, E., Mendoza-Denton, R., & Tropp, L. R. (2008). With a little help from my cross-group friend: Reducing anxiety in intergroup contexts through cross-group friendships. Journal of Personality and Social Psychology, 95, 1080-1094. – experimentally induced cross-group friendships between white and Latino students, and showed that this reduced cortisol stress reactivity and increased intergroup interactions among those highest in race-based anxiety and implicit racial prejudice.


Pettigrew, T. F., & Tropp, L. R. (2006). A meta-analytic test of intergroup contact theory. Journal of Personality and Social Psychology90, 751-783. – provides a meta-analytic test of the contact hypothesis, and finds that Allport was right: intergroup contact really does reduce intergroup prejudice.


Poteat, V. P., Mereish, E. H., Liu, M. L., & Nam, J. S. (2011). Can friendships be bipartisan? The effects of political ideology on peer relationships. Group Processes & Intergroup Relations, 14, 819-834. – shows that ideology and partisanship can make personal relationships particularly difficult, but that those with positive interpartisan friendships have more positive attitudes to their ideological opponents.



2.2. Emphasize Superordinate Goals 


In intergroup situations, superordinate goals are those that transcend group boundaries, often requiring cooperation between the groups. For instance, preventing global warming is not just a goal for any one specific nation, but is a superordinate goal requiring cooperation between many nations. Another classic idea and finding in social psychology comes from the “Robber’s Cave” experiment led by Muzafer and Carolyn Sherif in the 1950s. The researchers sought to study the dynamics of intergroup attitudes by dividing boys at summer camp into two competitive teams, the Eagles and the Rattlers. The boys quickly developed negative attitudes and stereotypes about members of the opposing team, and engaged in hostile intergroup actions such as looting each other’s cabins and burning each other’s team flags. But things changed dramatically when the two teams were brought together and given superordinate goals that they had to work together to achieve: these goals reduced intergroup animosity to the point that by the end of the camp the boys elected to ride back together, and did not divide even by teams when they sat on the bus. Since this landmark demonstration study, social psychologists have continued to find that superordinate goals improve intergroup relations, and the lessons from Robber’s Cave are now being applied to partisan gridlock as well.


2.2.1. Annotated Bibliography: Using Superordinate Goals to Improve Intergroup Relations


Haidt, J. (2012). How common threats can make common (political) ground. Presentation at TED. – provides an argument that ideological opponents can put aside their differences and work together if they acknowledge the superordinate threats recognized by the other side (see also Haidt’s Asteroids Club project).


Motyl, M., Hart, J., Pyszczynski, T., Weise, D., Cox, C., Maxfield, M., & Siedel, A. (2011). Subtle priming of shared human experiences eliminates threat-induced negativity toward Arabs, immigrants, and peace-making. Journal of Experimental Social Psychology, 47, 1179-1184.


Pyszczynski, T., Solomon, S., & Greenberg, J. (2003). Black Tuesday: The Psychological Impact of 9/11. American Psychological Association. – shows increased cooperation between liberals and conservatives in the U.S. following the attacks of 9/11/2001.


Pyszczynski, T., Motyl, M., Vail III, K. E., Hirschberger, G., Arndt, J., & Kesebir, P. (2012). Drawing Attention to Global Climate Change Decreases Support for War. Peace and Conflict: Journal of Peace Psychology18, 354-368. – demonstrated that prompting people to consider the potential negative consequences of global warming led to improved intergroup relations in terms of support for using extreme military tactics, support for war, support for peace-making and diplomacy, and support for the use of terrorist attacks. Importantly, this effect was not limited to American college students. Rather, this effect was shown for liberals and conservatives in the United States and replicated in Israel and Palestine on non-student populations during the 2009 bombings, and in Iran among fundamentalist Muslims [from Motyl, in press].


Sherif, M., Harvey, O. J., White, B. J., Hood, W. R., & Sherif, C. W. (1961). Intergroup conflict and cooperation: The Robber’s Cave experiment (Vol. 10). Norman, OK: University Book Exchange. And Sherif, M. (1958). Superordinate goals in the reduction of intergroup conflict. The American Journal of Sociology, 63, 349-356. – describes the classic “Robber’s Cave” study, in which summer camp boys divided into competing groups show reduced intergroup hostility when given superordinate goals requiring their cooperation.



3. What Shows Promise: Future Directions


3.1. Reducing Moral Certainty


Multiple lines of morality research, form moral convictions to moral foundations, have suggested that there are dangers to human morality:  our moral nature may help us to cooperate within groups, but it also makes us more likely to fear and denigrate outgroups. There is suggestive evidence that intergroup relations can be improved by “de-moralizing” situations – that is, getting people to see intergroup situations in less moralized ways. This could be done by priming financial or material self-interest, increasing the influence of moderates, or decreasing the influence of ideological and moral extremists in group contexts. However, most of the findings below don’t directly manipulate moralization, and so the evidence remains more indirect and suggestive for the time being.


3.1.1. Annotated Bibliography: Reducing Moral Certainty to Improve Intergroup Relations


Fernbach, P. M., Rogers, T., Fox, C. R., & Sloman, S. A. (2013). Political extremism is supported by an illusion of understanding. Psychological Science, 24, 939-946. – provides evidence that part of ideological extremism is the false belief that one knows more than one actually does. Further, experimental manipulations requiring participants to provide details and mechanistic explanations reduced partisanship in both attitudes and behavior (see our study summaries here, here, and here).


Graham, J., Iyer, R., Haidt, J., & Motyl, M. S. (2010, January). Around the maypole: Religions foster group-focused morality. Presented to the Society for Personality and Social Psychology annual conference, Las Vegas, NV. – presented an experiment manipulating whether participants responded to a conflictual intergroup situation in terms of what is morally right, or in terms of what’s in their pragmatic interest. Those in the morality condition were more likely to support acts of violence and aggression against the outgroup (except the religious, who supported outgroup aggression in both conditions).


Nasie, M., Bar-Tal, D., Pliskin, R., Nahhas, E., Haperin, E., (2014) Overcoming the Barrier of Narrative Adherence in Conflicts Through Awareness of the Psychological Bias of Naive Realism. Personal and Social Psychology Bulletin, 40, 1543-1557. – provides evidence that teaching about naïve realism (thinking your own view is the truth, while your opponents’ views are ideologically biased) can reduce partisan hostility (see our study summary here).


Pilecki, A. (2014). When morality threatens civility. – summarizes multiple lines of research showing how morality can stand in the way of compromise and increase rigidity and partisanship.


Iyer, R. (2014). Pew research highlights social, political and moral polarization among partisans, but more people are still moderates. – summarizes a recent nationally representative Pew poll that shows an increasing minority in the U.S. are morally and ideologically extreme (and polarized), but points out that most Americans are still moderates.


Skitka, L. J., & Mullen, E. (2002). The dark side of moral conviction. Analyses of Social Issues and Public Policy2, 35-41. – reviews evidence that moral convictions can cause people to disregard due process and other safeguards of civil society, contributing to both terrorism and violations of civil liberties to stop terrorism.


Waytz, A., Young, L., & Ginges, J. (2014). Motive attribution asymmetry for love vs. hate drives intractable conflict. Proceedings of the National Academy of Sciences, 111(44), 15687-15692. – provides evidence that people attribute ingroup-love motivations to their own group, and outgroup-hate motivations to outgroups. This bias was eliminated when participants had monetary incentives to be correct about the other side. It’s possible that this works in part by “unmoralizing” the situation, moving it to the profane value of money (for study summaries see here, here, and here).



3.2. Emphasizing Shared Humanity


Promoting a sense that outgroup members share basic human characteristics and desires may lead to improved intergroup relations, without any negative consequences for the individual. In a series of studies, Motyl, Hart, and colleagues (2011) demonstrated that eliciting a sense shared humanity through depicting basic human activities (like eating dinner with one’s family) or asking people to reflect on positive or negative childhood experiences led to reduced implicit hostility against Arabs, reduced support for war, and increased support for using peaceful diplomatic means in resolving international disputes. Furthermore, these effects were mediated by the sense that members of outgroups had shared experiences and were similar to ingroup members in simple, human ways. These findings are encouraging, although rely on making salient to individuals ways in which outgroup members may be similar to them and this intervention may be particularly short-lived. [from Motyl, in press]


Motyl, M., Hart, J., Pyszczynski, T., Weise, D., Cox, C., Maxfield, M., & Siedel, A. (2011). Subtle priming of shared human experiences eliminates threat-induced negativity toward Arabs, immigrants, and peace-making. Journal of Experimental Social Psychology, 47, 1179-1184.



3.3. Expressing Ingroup Love without Outgroup Hate


In an intergroup cooperative economic game study, allowing the members of 3-person cooperative teams to express ingroup love reduced intergroup conflict. It is not yet clear how these results would generalize outside economic games. See our study summary here.


Halevy, N., Weisel, O., & Bornstein, G. (2012). “In‐Group Love” and “Out‐Group Hate” in Repeated Interaction Between Groups. Journal of Behavioral Decision Making, 25, 188-195.



3.4. Reducing Zero-Sum Perceptions


In a novel highly-powered study, Ebersole and colleagues pit five different partisanship-reducing interventions against each other, compared to a control group: 1. self-affirmation (see section 2.1 above), 2. superordinate threats (see section 2.2 above), 3. knowing group membership last (so ingroup biases don’t affect first impressions), 4. observing civility in others, and 5. reducing zero-sum perceptions. Using explicit and implicit attitude measures toward Democrats and Republicans as the dependent variables, the team found that all measures reduced partisan hostility, but only one did so approaching a significant difference from the control group. In this condition, participants read a passage about how politics is not a zero-sum game, and how both sides could get more if they worked together. For more on this study, see our study summary here, materials here, and study information on the Open Science Framework here.



4. Conclusion


Most of the research on political partisanship – and on intergroup conflict more generally – details how pervasive and intractable these phenomena can be. (In fact, ideological bias seems to be even stronger than racial bias in the U.S. – see study summaries here and here.) In this annotated bibliography I have tried to highlight what can be done about it – that is, what can be done to reduce partisanship, ideological extremism, ingroup bias, and intergroup strife. In general, the most empirically-supported methods for improving intergroup relations both have their origins in classic psychology: 1. Promoting cross-group interpersonal interactions, and 2. Groups being faced with superordinate goals requiring intergroup cooperation. In addition, reducing moral certainty shows promise for reducing extremism in ideological partisanship and other intergroup conflicts, as does emphasizing shared humanity and reducing zero-sum perceptions of intergroup contexts. In my opinion, interventions designed to reduce moral certainty (and moralization in general) show the most promise for reducing intergroup hostility, and represent the area where future research is most sorely needed. There is clearly a lot more to be done. But the fact that intergroup relations have been empirically demonstrated to be improved by a variety of experimental interventions has implications for the future of civil politics that can be summarized in two words: there’s hope.