Amad a vuestros enemigos. Arthur C. Brooks
Siblings Endorse Rival in New Campaign Ads», Phoenix New Times, 21 de septiembre de 2018, https://www.phoenixnewtimes.com/news/arizona-congressman-paul-gosars-siblings-endorse-opponent-10849863.
18. Paul Gosar (@DrPaulGosar), «My siblings who chose to film ads against me are all liberal Democrats who hate President Trump. These disgruntled Hillary supporters are related by blood to me but like leftists everywhere, they put political ideology before family. Stalin would be proud. #Az04 #MAGA2018», Twitter, 22 de septiembre de 2018, 11:24 h.
19. David A. Graham, «Really, Would You Let Your Daughter Marry a Democrat?» Atlantic, 27 de septiembre de 2012, https://www.theatlantic.com/politics/archive/2012/09/really-would-you-let-your-daughter-marry-a-democrat/262959.
20. Thomas Jefferson, «From Thomas Jefferson to Henry Lee, 10 August 1824», Rotunda, http://rotunda.upress.virginia.edu/founders/default.xqy?keys=FOEA-print-04-02-02-4451.
21. Agneta H. Fischer e Ira J. Roseman, «Beat Them or Ban Them: The Characteristics and Social Functions of Anger and Contempt».
22. Kirsten Weir, «The Pain of Social Rejection», American Psychological Association, Monitor on Psychology, 43, 4, abril de 2012, p. 50, http://www.apa.org/monitor/2012/04/rejection.aspx.
23. Weir, id.
24. Stephen Hawkins et al., «Hidden Tribes: A Study of America’s Polarized Landscape», More in Common, 2018, https://static1.squarespace.com/static/5a70a7c3010027736a22740f/t/5bbcea6b7817f-7bf7342b718/1539107467397/hidden_tribes_report-2.pdf.
25. John Wagner y Scott Clement, «‘It’s Just Messed Up’: Most Think Political Divisions as Bad as Vietnam Era, New Poll Shows», Washington Post, 28 de octubre de 2017, https://www.washingtonpost.com/graphics/2017/national/democracy-poll/?utm_term=.c6b95de49f42.
26. «APA Stress in America Survey: US at ‘Lowest Point We Can Remember’; Future of Nation Most Commonly Reported Source of Stress», American Psychological Association, 1 de noviembre de 2017, http://www.apa.org/news/press/releases/2017/11/lowest-point.aspx.
27. APA, Id.
28. «Many See Potential Harm from Future Gridlock, for the Nation and Personally», Pew Research Center, 11 de diciembre de 2014, http://www.people-press.org/2014/12/11/few-see-quick-cure-for-nations-political-divisions/12-11-2014_02.
29. Joshua Bleiberg y Darrell M. West, «Political Polarization on Facebook», 13 de mayo de 2015, https://www.brookings.edu/blog/techtank/2015/05/13/political-polarization-on-facebook.
30. Itai Himelboim, Stephen McCreery y Marc Smith, «Birds of a Feather Tweet Together: Integrating Network and Content Analysis to Examine Cross-Ideology Exposure on Twitter», Journal of Computer-Mediated Communication, 18, 2, enero de 2013, pp. 40-60, DOI: 10.1111/jcc4.12001.
31. Neil Malhotra y Gregory Huber, «Dimensions of Political Homophily: Isolating Choice Homophily along Political Characteristics», Stanford Graduate School of Business Working Paper n.° 3108, octubre de 2013, https://www.gsb.stanford.edu/faculty-research/working-papers/dimensions-political-homophily-isolating-choice-homophily-along.
32. «Partisan Animosity, Personal Politics, Views of Trump», Pew Research Center, 5 de octubre de 2017, http://www.people-press.org/2017/10/05/8-partisan-animosity-personal-politics-views-of-trump.
33. Id.
34. «Partisanship and Political Animosity in 2016», Pew Research Center, 22 de junio de 2016, http://www.people-press.org/2016/06/22/partisanship-and-political-animosity-in-2016.
35. David Blankenhorn, «The Top 14 Causes of Political Polarization», American Interest, 16 de mayo de 2018, https://www.the-american-interest.com/2018/05/16/the-top-14-causes-of-political-polarization.
36. «Reelection Rates over the Years», Open Secrets, Center for Responsive Politics, https://www.opensecrets.org/overview/reelect.php. Los resultados corresponden a las elecciones de 2012, 2014 y 2016; en el momento de escribir este libro, aún no estaban disponibles los resultados de las elecciones de mitad de mandato de 2018, pero es muy probable que la proporción de representantes y senadores reelegidos sea parecida a la de las elecciones previas: superior al 90 por ciento.
37. Matthew D. Lieberman, Social: Why Our Brains Are Wired to Connect, Nueva York, Crown, 2013, p. 247.
38. Id.
39. Julianne Holt-Lunstad, Timothy B. Smith y J. Bradley Layton, «Social Relationships and Mortality Risk: A Meta-analytic Review», PLOS Medicine, 7, 7, julio de 2010. DOI: 10.1371/journal. pmed.1000316.
40. «The Health Benefits of Strong Relationships», Harvard Women’s Health Watch, diciembre de 2010, https://www.health.harvard.edu/newsletter_article/the-health-benefits-of-strong-relationships.