Collaborating Authors

Johnny Manziel Controversy Timeline: The Heisman-Winning Quarterback's Numerous Off-The-Field Incidents

International Business Times

It has been a long fall from grace for NFL free agent quarterback Johnny Manziel, who as a Texas A&M University freshman rocketed to fame while scrambling his way to a Heisman award. Some four years later, amid myriad personal and professional setbacks, a grand jury is scheduled to hear a case Thursday against Manziel from Dallas prosecutors. The 23-year-old stands accused of hitting his ex-girlfriend in a January incident, and a grand jury could issue a decision to indict Manziel as soon as Monday. If he's not indicted, the public could find out as soon as Thursday. For the better part of his NFL career with the Cleveland Browns, questions about Manziel's lifestyle have abounded.

German Minister on Brexit: Cohesion of EU27 Has Priority

U.S. News

BERLIN (Reuters) - Germany is ready to help Britain on Brexit within the framework set by the European Union but the cohesion of the bloc's remaining 27 members must take priority, German Agriculture Minister Julia Kloeckner said on Wednesday.

Merkel Seeks Cohesion and Renewal in Angst-Ridden Germany

U.S. News

Playing on the catchphrase "wir schaffen das" ("we can do this") that she employed at the height of the refugee crisis, Merkel said Germany could become a more cohesive society and make the technological advances to be ready for the future.

Network, Popularity and Social Cohesion: A Game-Theoretic Approach

AAAI Conferences

In studies of social dynamics, cohesion refers to a group's tendency to stay in unity, which -- as argued in sociometry — arises from the network topology of interpersonal ties. We follow this idea and propose a game-based model of cohesion that not only relies on the social network, but also reflects individuals' social needs. In particular, our model is a type of cooperative games where players may gain popularity by strategically forming groups. A group is socially cohesive if the grand coalition is core stable. We study social cohesion in some special types of graphs and draw a link between social cohesion and a classical notion of structural cohesion by White and Harary. We then focus on the problem of deciding whether a given social network is socially cohesive and show that this problem is CoNP-complete. Nevertheless, we give two efficient heuristics for coalition structures where players enjoy high popularity and experimentally evaluate their performances.

Can playing together help us live together?


The contact hypothesis in psychology predicts that prejudice can be reduced when rival groups come together under optimal circumstances of cooperation and equal status. To date, the weight of real-world evidence for this hypothesis comes from self-reported attitudes after self-initiated contact, not from preregistered randomized trials that take intergroup contact as seriously as one would take a potential vaccine for conflict ([ 1 ][1], [ 2 ][2]). Consequently, on page 866 of this issue, the results of Mousa's ([ 3 ][3]) new field experiment are breaking news. Mousa intervened in amateur Christian soccer leagues across Northern Iraqi cities affected by ISIS violence. To assess the impact of this ambitious real-world intervention, she randomly assigned Muslim players to half of the teams, measured players' behavior up to 6 months later, and posted her preregistered analysis plan and data alongside the report. Mousa finds that having Muslim teammates causes Christian players to change their behavior for the better toward Muslim players, by including them, working with them, and awarding them material signs of respect. Team-based contact with minority group members reduced prejudiced behavior toward other minority group players. Given its relevance for policy (Mousa notes that $877 million was allocated in 2020 toward “social cohesion” programming by the U.S. Agency for International Development) and that the contact hypothesis has been studied for many years, some may classify this research as an application of a well-known finding. This would be inaccurate. Previous research has not demonstrated cause and effect with real-world interventions or measured behaviors or otherwise leveraged the most robust research methodologies. These methods are crucial, given that the anticipated effects of contact range from positive change to backlash, in which contact stirs latent resentments. This makes Mousa's research more similar to basic science that makes progress toward fundamental evidence than to applied research that tests policy interventions based on a robust foundation of scientific evidence. Work in the field, which is often mistaken for applied research because of its location outside the laboratory, performs the function of basic science when it comes to the question of whether intergroup contact increases social cohesion. The study presents a fundamental theoretical puzzle: Why don't the positive behavioral effects generalize out of context, or to positive intergroup attitudes? The first piece of the puzzle is that the observed changes are limited to behaviors and not attitudes. A growing number of field experiments on prejudice reduction uncover this pattern ([ 4 ][4], [ 5 ][5]), which counters both lay and scientific notions that attitudes guide behavior. One could argue that between attitudes and behaviors, it is better to change behavior because prejudicial action is worse than harboring prejudicial attitudes. Additionally, public behaviors may cause more downstream change because they are more easily observable than private attitudes ([ 6 ][6]). More work is needed to measure these kinds of spillover effects, following on Mousa's finding that community members who attended more games were more likely to view religious and ethnic divisions as arbitrary. Future work can also disentangle whether attitudes are simply more difficult to change or whether current research is not measuring the correct attitudes. Perhaps the nature of intergroup contact is useful for changing a more limited range of attitudes than those measured in the present study. Mousa observes one instance of attitude change among players: the item regarding arbitrary religious and ethnic divisions. She points out that it represents a change in “abstract attitudes rather than concrete policy positions.” As it was originally conceived, the contact hypothesis was a salve for prejudice or animus, not for antagonistic political opinion or behavior ([ 7 ][7]). Since then, psychological evidence has grown, suggesting that prejudice-reduction interventions have inconsistent and even unintended effects on related political attitudes ([ 8 ][8]). Mousa defines and measures the target of her intervention, social cohesion, as a more compound concept than prejudice, involving intergroup cooperation and policy attitudes. Interventions such as contact that are intended to soften attitudes toward outgroups may need to be combined with additional activities to channel newfound goodwill into a political or policy position. Early work on interracial contact in the United States recognized this point. For example, in addition to creating ideal contact conditions for Black and White individuals working in teams, one study using Black actors to mention instances of discrimination and race-based hardship helped White participants connect their experience to larger societal issues ([ 9 ][9]). The second piece of the theoretical puzzle is that changes in behavior toward other Muslim players in the league did not generalize to changes in behavior toward Muslim strangers. Mousa offers possible explanations, including ongoing threat from recent anti-Christian violence, the fragile quality of the contact with other players, and the possibility that behavior change takes longer to manifest. Another possibility rests in the basic math of the league's intergroup contact: Christian leaders allowed a maximum of three Muslim players on treatment teams. This limitation represents a hard-won insight about the difficulty of implementing intergroup contact interventions in post-conflict settings but may have limited the generalizability of behavioral effects. Psychological theory predicts that individuals can make positive generalizations from one prototypical group member to the rest of the group ([ 10 ][10]). The handful of Muslim players may have been seen as exceptional, not prototypical, in the eyes of the Christian players, similar to other contexts with a token number of outgroup individuals. If the Muslim players were considered an exception to the rule, psychological theory would not predict that positive impressions of Muslim players would generalize to their group. Another consequence of the small number of Muslim players is that it inhibits the research from exploring effects on both sides of the intergroup contact. Mousa's data suggest that Muslim players' prejudice did not change over time, but there are too few Muslims and no Muslim control group to rigorously test this claim. Leaving out the perspectives of minority group members, who are often instrumentalized for the purpose of attitude change among the majority, is a pattern in intergroup contact research. There is much to learn by studying reactions to intergroup contact among minority group participants. This landmark study cuts a clear path for future scholarship. Generalized answers will only emerge after more experimental work that may seem like policy application but is actually basic science, working systematically toward robust conclusions. Mousa is one of a cohort ([ 2 ][2]) of young scientists who are leading the way. 1. [↵][11]1. E. L. Paluck, 2. S. A. Green, 3. D. P. Green , Behav. Pub. Pol. 3, 129 (2019). [OpenUrl][12] 2. [↵][13]1. E. L. Paluck , Harvard Dataverse (2020); doi:10.7910/DVN/ODACR5. 3. [↵][14]1. S. Mousa , Science 369, 866 (2020). [OpenUrl][15][Abstract/FREE Full Text][16] 4. [↵][17]1. A. Scacco, 2. S. S. Warren , Am. Polit. Sci. Rev. 112, 654 (2018). [OpenUrl][18][CrossRef][19] 5. [↵][20]1. E. L. Paluck , J. Pers. Soc. Psychol. 96, 574 (2009). [OpenUrl][21][CrossRef][22][PubMed][23][Web of Science][24] 6. [↵][25]1. T. Kuran , Private Truths, Public Lies (Harvard Univ. Press, 1997). 7. [↵][26]1. G. Allport , The Nature of Prejudice (Addison Wesley, 1954). 8. [↵][27]1. J. Dixon, 2. M. Levine, 3. S. Reicher, 4. K. Durrheim , Behav. Brain Sci. 35, 411 (2012). [OpenUrl][28][CrossRef][29][PubMed][30] 9. [↵][31]1. S. W. Cook , J. Res. Dev. Educ. 55, 647 (1978). [OpenUrl][32] 10. [↵][33]1. J. C. Turner, 2. M. A. Hogg, 3. P. J. Oakes, 4. S. D. Reicher, 5. M. S. Wetherell , Rediscovering the Social Group, A Self-Categorization Theory (Basil Blackwell, 1987). Acknowledgments: The authors thank the Rita Allen Foundation for funding and R. Porat and D. Green for comments. [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: #ref-5 [6]: #ref-6 [7]: #ref-7 [8]: #ref-8 [9]: #ref-9 [10]: #ref-10 [11]: #xref-ref-1-1 "View reference 1 in text" [12]: {openurl}?query=rft.jtitle%253DBehav.%2BPub.%2BPol.%26rft.volume%253D3%26rft.spage%253D129%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [13]: #xref-ref-2-1 "View reference 2 in text" [14]: #xref-ref-3-1 "View reference 3 in text" [15]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DMousa%26rft.auinit1%253DS.%26rft.volume%253D369%26rft.issue%253D6505%26rft.spage%253D866%26rft.epage%253D870%26rft.atitle%253DBuilding%2Bsocial%2Bcohesion%2Bbetween%2BChristians%2Band%2BMuslims%2Bthrough%2Bsoccer%2Bin%2Bpost-ISIS%2BIraq%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.abb3153%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [16]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEyOiIzNjkvNjUwNS84NjYiO3M6NDoiYXRvbSI7czoyMjoiL3NjaS8zNjkvNjUwNS83NjkuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9 [17]: #xref-ref-4-1 "View reference 4 in text" [18]: {openurl}?query=rft.jtitle%253DAm.%2BPolit.%2BSci.%2BRev.%26rft.volume%253D112%26rft.spage%253D654%26rft_id%253Dinfo%253Adoi%252F10.1017%252FS0003055418000151%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [19]: /lookup/external-ref?access_num=10.1017/S0003055418000151&link_type=DOI [20]: #xref-ref-5-1 "View reference 5 in text" [21]: {openurl}?query=rft.jtitle%253DJournal%2Bof%2Bpersonality%2Band%2Bsocial%2Bpsychology%26rft.stitle%253DJ%2BPers%2BSoc%2BPsychol%26rft.aulast%253DPaluck%26rft.auinit1%253DE.%2BL.%26rft.volume%253D96%26rft.issue%253D3%26rft.spage%253D574%26rft.epage%253D587%26rft.atitle%253DReducing%2Bintergroup%2Bprejudice%2Band%2Bconflict%2Busing%2Bthe%2Bmedia%253A%2Ba%2Bfield%2Bexperiment%2Bin%2BRwanda.%26rft_id%253Dinfo%253Adoi%252F10.1037%252Fa0011989%26rft_id%253Dinfo%253Apmid%252F19254104%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [22]: /lookup/external-ref?access_num=10.1037/a0011989&link_type=DOI [23]: /lookup/external-ref?access_num=19254104&link_type=MED&atom=%2Fsci%2F369%2F6505%2F769.atom [24]: /lookup/external-ref?access_num=000263729700005&link_type=ISI [25]: #xref-ref-6-1 "View reference 6 in text" [26]: #xref-ref-7-1 "View reference 7 in text" [27]: #xref-ref-8-1 "View reference 8 in text" [28]: {openurl}?query=rft.jtitle%253DBehav.%2BBrain%2BSci.%26rft.volume%253D35%26rft.spage%253D411%26rft_id%253Dinfo%253Adoi%252F10.1017%252FS0140525X11002214%26rft_id%253Dinfo%253Apmid%252F23164194%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [29]: /lookup/external-ref?access_num=10.1017/S0140525X11002214&link_type=DOI [30]: /lookup/external-ref?access_num=23164194&link_type=MED&atom=%2Fsci%2F369%2F6505%2F769.atom [31]: #xref-ref-9-1 "View reference 9 in text" [32]: {openurl}?query=rft.jtitle%253DJ.%2BRes.%2BDev.%2BEduc.%26rft.volume%253D55%26rft.spage%253D647%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [33]: #xref-ref-10-1 "View reference 10 in text"