Politicians polarize and experts depolarize public
support for COVID-19 management policies
across countries
Alexandra Floresa,1, Jennifer C. Colea,b,1, Stephan Dickertc,d, Kimin Eome, Gabriela M. Jiga-Boyf , Tehila Kogutg ,
Riley Loriaa, Marcus Mayorgah , Eric J. Pedersena, Beatriz Pereirai , Enrico Rubaltellij , David K. Shermank,
Paul Slovich,l,2 , Daniel Va€stfja€llh,m, and Leaf Van Bovena,2
aDepartment of Psychology & Neuroscience, University of Colorado Boulder, Boulder, CO 80309; bClimate Change Research Network, Vanderbilt University,
Nashville, TN 37203; cSchool of Business andManagement, QueenMary University of London, London E1 4NS, United Kingdom; dDepartment of Psychology,
University of Klagenfurt 9020 Klagenfurt, Austria; eSchool of Social Sciences, SingaporeManagement University, Singapore 188065; fSchool of Psychology,
Swansea University, Swansea SA2 8PP, United Kingdom; gDepartment of Education, Ben-Gurion University of the Negev, Be’er Sheva 8400711, Israel; hDecision
Research, Eugene, OR 97401; iDepartment ofMarketing, Ivy College of Business, Iowa State University, Ames, IA 50011; jDepartment of Developmental
Psychology and Socialization, University of Padua 35131 Padua, Italy; kDepartment of Psychological & Brain Sciences, University of California, Santa Barbara,
CA 93106; lDepartment of Psychology, University of Oregon, Eugene, OR 97403; and mDepartment of Behavioural Sciences and Learning, Division of
Psychology, Linko€ping University SE-581 83 Linko€ping, Sweden
Contributed by Paul Slovic; received September 24, 2021; accepted November 25, 2021; reviewed by Jonathan Schuldt and Keith Stanovich
Political polarization impeded public support for policies to reduce polarizing impact of cues from political elites is often described
the spread of COVID-19, much as polarization hinders responses to as a pathology especially pronounced in the United States (9,
other contemporary challenges. Unlike previous theory and research 10). Theories developed to explain polarized reactions to political
that focused on the United States, the present research examined cues have been largely developed within, and thus tend to focus
the effects of political elite cues and affective polarization on sup- on, the United States (9, 11, 12). We contend that such American
port for policies to manage the COVID-19 pandemic in seven coun- exceptionalism (13) is unwarranted and that these polarizing pro-
tries (n = 12,955): Brazil, Israel, Italy, South Korea, Sweden, the cesses should occur wherever people form political ingroups and
United Kingdom, and the United States. Across countries, cues from outgroups. We gauged public support for COVID-19 policies
political elites polarized public attitudes toward COVID-19 policies. after manipulating whether policies were attributed to liberal or
Liberal and conservative respondents supported policies proposed conservative political elites, with the experiment conducted simul-
by ingroup politicians and parties more than the same policies from taneously in Brazil, Israel, Italy, South Korea, Sweden, the
outgroup politicians and parties. Respondents disliked, distrusted, United Kingdom, and the United States. This span of countries
and felt cold toward outgroup political elites, whereas they liked, includes two-party and multiparty systems, liberal and conserva-
trusted, and felt warm toward both ingroup political elites and tive ruling parties, cultures that range in collectivism, differences
nonpartisan experts. This affective polarizationwas correlated with in overarching political ideologies, and different experiences with
policy support. These findings imply that policies from bipartisan the unfolding pandemic, as well as the stringency of policies
coalitions and nonpartisan experts would be less polarizing, enjoy- enacted to manage it (see SI Appendix, Table S2).
ing broader public support. Indeed, across countries, policies from
bipartisan coalitions and experts were more widely supported. A Significance
follow-up experiment replicated these findings among US respond-
ents considering international vaccine distribution policies. The
polarizing effects of partisan elites and affective polarization Political polarization impeded public support for policies to
emerged across nations that vary in cultures, ideologies, and politi- address the spread of COVID-19, much as polarization hin-
cal systems. Contrary to some propositions, the United States was ders responses to other societal challenges. The present
not exceptionally polarized. Rather, these results suggest that cross-country study demonstrates how the cues from politi-
polarizing processes emerged simply from categorizing people into cal elites and affective polarization are analogous across
political ingroups and outgroups. Political elites drive polarization countries addressing COVID-19. Far from being an outlier,
globally, but nonpartisan experts can help resolve the conflicts that the United States faces polarization challenges similar to
arise from it. those of other countries. Importantly, the results demon-
strate that policies to combat public health crises are more
COVID-19 j cross-country comparisons j political polarization j affective supported when proposed by nonpartisan experts and bipar-
polarization j expertise tisan coalitions of political leaders. These results provide
clear guidance on depolarizing communication strategies to
improve global responses to health crises.
By the summer of 2020, the world had largely converged ontwo key COVID-19 policy aims: fewer cases and deaths (1) Author contributions: A.F., J.C.C., S.D., K.E., G.M.J.-B., T.K., R.L., M.M., E.J.P., B.P., E.R.,
and more robust economic recovery efforts (2). Yet, policies D.K.S., P.S., D.V., and L.V.B. designed research; A.F., J.C.C., E.J.P., and L.V.B. performed
designed to attain these goals were met with politically polar- research; A.F., J.C.C., E.J.P., and L.V.B. analyzed data; and A.F., J.C.C., and L.V.B. wrote
ized responses worldwide, undermining broad public support the paper. All authors reviewed and commented on manuscript drafts.
(3–5). As with climate change, rising economic inequality, and Reviewers: J.S., Cornell University; and K.S., University of Toronto.
other contemporary crises, human behavior both contributes to The authors declare no competing interest.
the spread of and is a solution to the COVID-19 pandemic (6). This open access article is distributed under Creative Commons Attribution-
NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).
Political polarization undermines the cooperation required to 1A.F. and J.C.C. contributed equally to this work.
enact behavioral change, posing an endemic barrier to effec- 2To whom correspondence may be addressed. Email: pslovic@uoregon.edu or
tively addressing such challenges (7, 8). vanboven@colorado.edu.
We suggest that polarized public opinion toward COVID-19 This article contains supporting information online at http://www.pnas.org/lookup/
policies emerged globally merely because said policies were asso- suppl/doi:10.1073/pnas.2117543119/-/DCSupplemental.
ciated with opposing political parties and politicians. The Published January 18, 2022.
PNAS 2022 Vol. 119 No. 3 e2117543119 https://doi.org/10.1073/pnas.2117543119 j 1 of 7
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We reason that polarized public opinion in response to political (33) the overall level of affective polarization may be similar
elites reflects a widespread human tendency to categorize people across countries (34).
into political ingroups and outgroups and to respond to cues from
those groups (14, 15). This political categorization engenders Depolarizing Experts and Bipartisan Coalitions. The analysis that
social, affective, and cognitive processes that divide public opinion political elite cues are polarizing because of affective polariza-
when proposals are associated with political identities (9, 16–18). tion leads us to expect that cues from nonpartisan experts and
The commonality of these processes should result in similarly bipartisan coalitions will be less polarizing. People trust experts
polarizing effects across different countries. Understanding these more than they trust politicians, especially more than outgroup
effects within and outside the United States is therefore neces- politicians (35, 36). Experts are generally more persuasive than
sary for developing effective crisis communication strategies, thus nonexperts (37, 38), partly because expertise increases per-
fostering better responses to challenges like COVID-19. ceived source credibility (39). Although conservatives are some-
what less trusting and more skeptical of experts than liberals
Polarizing Political Elites. Prior research conducted in the United (35, 36), people worldwide report high confidence that nonpar-
States shows that people react to policies based not only on tisan scientific experts act in the public’s best interest (40).
their content but on the political identities of policy propo- COVID-19 policies proposed by experts should therefore be
nents. For instance, Democrats support climate policies pro- supported more than policies proposed by either liberal or con-
posed by Democratic politicians more than the same policies servative politicians.
proposed by Republican politicians, and vice versa for Republi- We similarly expect that COVID-19 policies from bipartisan
cans (19–21). The polarizing influence of cues from politicians, coalitions of liberal and conservative elites will be supported more
parties, and other political elites can be so strong that people than policies from only liberal or conservative politicians. Ordi-
nary people value political cooperation (41, 42) and are responsive
place “party over policy,” with partisans favoring ideologically
to whether proposals are backed by trusted political elites (43, 44).
misaligned policies from their political ingroup over ideologi-
Previous research suggests that people are more swayed by the
cally aligned policies from their political outgroup (19).
stances of their fellow ingroup than outgroup members (22, 23),
An underexamined question is whether political elite cues
making it unlikely that the mere presence of outgroup politicians
polarize public opinion in a similar way and to a similar degree
will completely dampen support for bipartisan policies. Examining
in countries beyond the United States. Direct cross-country policies proposed by bipartisan political coalitions thus allows us
comparisons of the polarizing effects of political cues have to assess whether bipartisan policies are supported similarly to
proven challenging because countries face different politicized ingroup policies, or if the presence of outgroup cues causes
policy issues. For instance, research in the United States has people to devalue those policies. We predict that both ordinary
examined how political elite cues polarize attitudes toward wel- liberals and conservatives will support bipartisan-backed poli-
fare policies (19) and climate policy (22–25), whereas research cies more than policies associated with the outgroup, given the
in other countries has examined infrastructure and drinking age presence of cues from trusted ingroup politicians.
policies (26). The shared experience of COVID-19 provides a
unique and important opportunity to make possible a direct Overview of Experiments. To test these predictions, we evaluated
comparison of political elite cues. responses to COVID-19 management policies and the political
Some researchers speculate that political elites may have a groups that proposed them across seven democratic nations:
greater polarizing impact in the United States because of its Brazil, Israel, Italy, South Korea, Sweden, the United King-
greater degree of ideological and cultural sorting (17, 27), more dom, and the United States (see SI Appendix, Table S2). To
polarized mainstream media (28), and more polarized political examine the generality of effect and respondents’ sensitivity to
leaders (29). Yet, to the extent that political elite cues polarize the type of policy, we included two policies, one emphasizing
because they tap widespread psychological processes arising public health and one emphasizing economic outcomes. We
from sociopolitical categorization, political cues should be simi- also evaluated responses to a COVID-19 vaccine distribution
larly polarizing across countries. For example, partisan identifi- policy among US respondents in a follow-up experiment.
cation predicts identity-defensive political behavior more The COVID-19 pandemic provided an important context for
strongly than ideology, even in multiparty systems like Italy, three reasons. First, COVID-19 confronted nations worldwide
Sweden, and the United Kingdom (30, 31). with similar policy concerns at about the same time, minimizing
cross-country confounding of policy domains. Second, polarized
Affective Polarization. An emerging explanation of why cues from public responses to COVID-19 policies were plausibly unex-
political elites polarize public opinion is that people distrust, dis- pected given that shared threats that require coordinated action,
like, and feel cold toward those in the political outgroup while like the pandemic, should reduce intergroup animosity and
trusting, liking, and feeling warmly toward those in their political increase cooperation (20, 22, 23). Also, because the coronavirus
ingroups (8–10). Such affective polarization motivates negative was novel, public opinion was not previously polarized on the
behaviors toward opposing political groups, including hiring dis- issue. Finally, because most low- and middle-wealth countries
crimination, prejudice, and reluctance to socialize with people require vaccine donations from wealthier nations to cover their
from opposing political parties (8–10). vaccine needs (45), US residents’ attitudes toward the distribu-
Researchers have suggested that affective polarization is tion of vaccines abroad can meaningfully affect the world’s
larger in the United States than in other countries (9), contrib- COVID-19 recovery efforts (46). The second experiment allowed
uting to the prediction that political elite cues should be more us to evaluate our hypotheses in a context involving a material
polarizing in the United States. We suggest, however, that good that is vital to global pandemic outcomes: the worldwide
affective polarization emerges from basic psychological pro- distribution of safe and effective COVID-19 vaccines.
cesses following from the categorization of people into political
ingroups and outgroups and should thus emerge across coun- Results: Cross-Country Evaluations of COVID-19
tries. The intergroup processes that arise from social categori- Management Policies
zation are pronounced when groups compete for power and Partisan Elites Polarize. Respondent support for COVID-19 poli-
status (32), as is true of political groups. Some evidence sug- cies was measured on 7-point bipolar scales. As predicted, across
gests that although the rate at which the United States has all seven countries liberal respondents supported policies more in
become polarized recently is greater than in other countries the liberal cues condition (mean [M] = 1.05) than in the
2 of 7 j PNAS Flores et al.
https://doi.org/10.1073/pnas.2117543119 Politicians polarize and experts depolarize public support for COVID-19
management policies across countries
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The partisan polarization effect emerged across countries
and was not significantly larger in the United States (P = 0.099;
Fig. 1B). Compared with the overall effect across countries (B =
0.63), the relevant interaction was significantly larger in Sweden
[B ¼ 1.13, F(1, 11,958) = 32.04, P < 0.001, η2p = 0.003] and Italy
[B ¼ 1.05, F(1, 11,958) = 21.98, P < 0.001, η2p = 0.002] and was sig-
nificantly smaller in the United Kingdom [B ¼ 0.04, F(1, 11,958) =
0.03, P = 0.864, η2p < 0.001].
Across countries, liberal respondents supported COVID-19
policies more (M = 0.99) than did conservative respondents
[M = 0.85; B ¼ –0.08, F(1, 11,958) = 7.80, P = 0.005, η2p =
0.001]. Notice, however, that the size of the difference between
liberal and conservative respondents (B = –0.08, η2p = 0.001) was
substantially smaller than the size of the interaction between
respondent partisan identification and political cues (B = 0.63, η2p
= 0.005). Results of the partisan polarization effect model are
summarized in Table 1. At least as much as liberals and conserva-
tives had polarized attitudes toward COVID-19 policies, the
direction and magnitude of those differences depended on
whether the policies were proposed by liberal or conservative
political elites.
Experts and Bipartisan Coalitions Depolarize.Respondents supported
policies proposed by nonpartisan experts and bipartisan coalitions
(M = 0.96) more than the same policies proposed by only liberal
or conservative elites [M = 0.78; B ¼ 0.20, F(1, 11,958) = 50.57,
P < 0.001, η2p = 0.004; Fig. 1A]. Respondent partisan identifica-
tion and political cues were collapsed into one factor (ingroup
versus outgroup), excluding respondents who did not identify
with either partisan group. Respondents reported lower support
for outgroup elites’ policies (M = 0.66) than for policies from
bipartisan coalitions [M = 0.93; B ¼ 0.34, F(1, 9,394) = 65.16,
P < 0.001, η2p = 0.007], experts [M = 0.99; B ¼ 0.40, F(1, 9,394) =
91.66, P < 0.001, η2p = 0.010], and ingroup elites [M = 1.00; B ¼
0.32, F(1, 9,394) = 56.61, P < 0.001, η2p = 0.006]. Respondents
did not differentiate between ingroup and bipartisan policies
Fig. 1. Political cues polarize public opinion toward COVID-19 across [B ¼ –0.03, F(1, 9,338) = 0.57, P = 0.448, η2p < 0.001]. Both
countries and policies, whereas bipartisan coalitions and experts depolar- expert and bipartisan policies were less polarizing than policies
ize public opinion. (A) Average policy support for economic versus public from either liberal or conservative elites, resulting in higher
health policies as a function of respondent partisan identification and overall policy support.
political cues. (B) Cross-country forest plot of the effect of political cues, The depolarizing effect of nonpartisan experts and bipartisan
the interaction between liberal or conservative cues and liberal or conser-
political elites occurred across countries (Fig. 1B). Compared
vative respondent partisan identification (blue markers), and support for
policies by bipartisan coalitions and experts versus policies from only lib- with the overall effect across countries (B = 0.20), the depolariz-
eral or conservative elites (gray markers), averaging across respondent par- ing effect of expert and bipartisan policies was significantly larger
tisan identification. Error bars represent 95% confidence intervals. in Sweden [B ¼ 0.37, F(1, 11,958) = 19.02, P < 0.001, η2p =
0.002], presumably because the polarizing effect of political cues
was also larger in Sweden. These results suggest that across
conservative cues condition [M = 0.66; B = –0.41, F(1, 11,958) = countries that vary on cultural, political, and demographic
51.96, P < 0.001, η2p = 0.004], and conservative respondents sup- dimensions, foregrounding either liberal or conservative political
ported policies more in the conservative cues condition (M = elites polarizes public opinion whereas foregrounding experts
0.93) than in the liberal cues condition [M = 0.66; B = 0.22, F(1, and bipartisan coalitions prevents polarization.
11,958) = 12.22, P < 0.001, η2p = 0.001]. This polarized pattern
produced a two-way interaction between respondent partisan Affective Polarization. Respondents across countries exhibited
identification (liberal or conservative) and the partisan cues affective polarization. A one-way ANOVA on averaged feelings of
manipulation [liberal or conservative; B = 0.63, F(1, 11,958) = liking, trust, and temperature toward liberal and conservative
54.83, P < 0.001, η2 = 0.005; Fig. 1A]. Centrists’ support did political elites and nonpartisan experts was significant [F(2,p 14,208) = 11,080.50, P < 0.001, η2
not differ between liberal and conservative cues conditions [B = p
= 0.609]. Respondents reported
negative affect toward outgroup political elites (M = –1.76) and
–0.12, F(1, 11,958) = 2.06, P = 0.151, η2p < 0.001]. positive affect toward both ingroup political elites [M = 0.65; B ¼
Respondents supported a policy emphasizing public health 2.22, F(1, 9,533) = 10,899.36, P < 0.001, η2p = 0.533] and experts
outcomes more (M = 1.26) than a policy emphasizing economic (M = 1.15). Respondents reported more positive affect toward
outcomes [M = 0.49; B ¼ –0.71, F(1, 11,958) = 642.67, P < 0.001, experts than toward ingroup political elites [B ¼ 0.66, F(1, 9,533)
η2p = 0.051; Fig. 1A]. A significant three-way interaction [B ¼ 0.50, = 1,479.02, P < 0.001, η2p = 0.134; Fig. 2A].
F(1, 11,958) = 8.79, P = 0.003, η2p = 0.001] indicated that the par- Affective polarization emerged as large, significant effects in
tisan polarization effect was larger in the economic emphasis con- all countries (Fig. 2B). Compared with the average affective
dition [B ¼ 0.88, F(1, 11,958) = 55.53, P < 0.001, η2p = 0.005] than polarization effect across countries (B ¼ 2.22) there were some-
in the public health emphasis condition [where it was still signifi- what smaller effects in Brazil [B ¼ 1.22, F(1, 9,533) = 372.41, P <
cant; B ¼ 0.38, F(1, 11,958) = 9.55, P = 0.002, η2p = 0.001]. 0.001, η2p = 0.038], South Korea [B ¼ 2.05, F(1, 9,533) = 814.30,
Flores et al. PNAS j 3 of 7
Politicians polarize and experts depolarize public support for COVID-19 https://doi.org/10.1073/pnas.2117543119
management policies across countries
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PSYCHOLOGICAL AND
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from political elites, nonpartisan experts, and bipartisan coa-
litions influence public support for COVID-19 policies. Peo-
ple support policies more when proposed by elites who they
trust and toward whom they feel positive.
Results: US Support for International Vaccine
Distribution Policies
The findings thus far demonstrate that cues from partisan elites
polarize public opinion toward COVID-19 policy across coun-
tries and that these polarizing effects are correlated with affec-
tive polarization. In a follow-up experiment, we examined how
these polarizing effects might continue to pose challenges as
societies confront global public health issues. Consider ques-
tions surrounding the distribution of vaccines that were devel-
oped and secured in wealthier countries such as the United
States with limited distribution in poorer countries. In addition
to the loss of life and economic activity in unvaccinated coun-
tries, unequal vaccine distribution increases the global risk of
new, vaccine-resistant variants of the virus (45, 46).
US respondents were asked to read one of two policies regard-
ing international vaccine distribution. An American prioritization
policy stated that because the United States had led vaccine devel-
opment, it “should be able to distribute vaccines to its people
before sending vaccines to other countries.” An internationally
Fig. 2. Affective polarization. People reported negative sentiment toward
outgroup elites and positive sentiment toward ingroup elites and especially
toward experts. (A) Average feelings of trust, liking, and warmth toward
liberal elites, conservative elites, and experts. (B) Cross-country forest plot
of affective polarization toward ingroup elites versus outgroup elites (red
markers) and affect toward experts versus ingroup elites (green markers).
Error bars represent 95% confidence intervals.
P < 0.001, η2p = 0.079], and the United Kingdom [B ¼ 2.17,
F(1, 9,533) = 1,122.79, P < 0.001, η2p = 0.105] and larger effects
in Sweden [B ¼ 2.99, F(1, 9,533) = 3,523.85, P < 0.001, η2p =
0.270] and the United States [B ¼ 2.84, F(1, 9,533) = 5,594.74,
P < 0.001, η2p = 0.370]. Although the size of these effects varied
somewhat across countries, the United States was not exceptional
in affective polarization.
Affective polarization was correlated with policy support.
Respondents’ support for COVID-19 policy was regressed on
their affect toward the group proposing the policy (using the
average of affect toward liberal and conservative elites for
bipartisan policies), controlling for political cue conditions,
respondent partisan identification, and policy emphasis (see
Table 2).* Respondents’ policy support was significantly and
positively predicted by their affect toward the policy proposer
[B = 0.20, F(1, 10,707) = 413.19, P < 0.001, η2p = 0.037]. This
effect emerged across countries, with the effect being somewhat
larger in the United States [B = 0.25, F(1, 10,707) = 239.85, P <
0.001, η2 = 0.022] compared with the average effect across Fig. 3. Political cues polarize public opinion in the United States toward vac-p cine distribution policies. (A) Average policy support for internationally propor-
countries. Affective polarization helps explain why cues
tional versus American prioritization policies as a function of respondent parti-
san identification and policy proponent. (B) Average feelings of trust, liking,
*We excluded centrists from the analysis of affective polarization of ingroups and and warmth toward Democratic elites, Republican elites, and experts, by respon-
outgroups. dent partisan identification.
4 of 7 j PNAS Flores et al.
https://doi.org/10.1073/pnas.2117543119 Politicians polarize and experts depolarize public support for COVID-19
management policies across countries
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Table 1. Multiple linear regression predicting respondents’ COVID-19 policy support from contrast-coded predictors for political cues,
respondent partisan identification, policy emphasis, and their interactions, including deviation coding for country
Statistic
Predictor B 95% CI SE F P
Political cues
P1: liberal vs. conservative 0.10 0.18, –0.02 0.040 6.60 0.010
P2: bipartisan vs. expert 0.10 0.02, 0.17 0.040 5.89 0.015
P3: liberal/conservative vs. bipartisan/expert 0.20 0.14, 0.25 0.028 50.57 <0.001
Respondent partisan identification
R1: liberal vs. conservative 0.08 0.14, –0.02 0.030 7.80 0.005
R2: centrist vs. liberal/conservative 0.15 0.21, –0.08 0.033 19.07 <0.001
Policy emphasis
E1: Public health vs. economic 0.71 0.77, –0.66 0.028 642.67 <0.001
Interactions: political cues × respondent partisan identification
P1 × R1 0.63 0.46, 0.80 0.085 54.83 <0.001
P1 × R2 0.03 0.21, 0.16 0.094 0.08 0.772
P2 × R1 0.10 0.26, 0.07 0.084 1.33 0.249
P2 × R2 0.14 0.05, 0.32 0.094 2.17 0.140
P3 × R1 0.17 0.28, –0.05 0.060 7.67 0.006
P3 × R2 0.05 0.18, 0.08 0.067 0.50 0.481
Interactions: political cues × policy emphasis
P1 × E1 0.12 0.04, 0.27 0.079 2.24 0.134
P2 × E1 0.06 0.21, 0.10 0.079 0.54 0.462
P3 × E1 0.14 0.03, 0.25 0.056 6.37 0.012
Interactions: respondent partisan identification × policy emphasis
R1 × E1 0.49 0.37, 0.61 0.060 66.83 <0.001
R2 × E1 0.02 0.15, 0.11 0.067 0.06 0.812
Interactions: political cues × respondent partisan identification × policy emphasis
P1 × R1 × E1 0.50 0.17, 0.84 0.170 8.79 0.003
P1 × R2 × E1 0.08 0.29, 0.45 0.188 0.18 0.672
P2 × R1 × E1 0.03 0.36, 0.30 0.168 0.03 0.869
P2 × R2 × E1 0.00 0.37, 0.37 0.189 0.00 0.981
P3 × R1 × E1 0.04 0.27, 0.19 0.119 0.11 0.740
P3 × R2 × E1 0.07 0.33, 0.19 0.133 0.28 0.597
proportional policy stated that “other countries should not be 0.015; Fig. 3A]. The direction of political polarization toward
punished for not having the means to fund vaccine trials” and that vaccine distribution policies depended on whether the policies
“vaccines should be distributed proportionally to country popula- were proposed by Democratic or Republican political elites.
tion size until 20% of each population is protected.”
Affective Polarization and Policy Support. Respondents reported
Partisan Elites Polarize, Experts and Bipartisan Coalitions Depolarize. negative affect toward outgroup political elites (M = –1.99) and
Both Democrats and Republicans supported the American pri- positive affect toward ingroup political elites [M = 1.07; B = 3.05,
oritization proposal more (M = 1.05) than the internationally F(1, 2,026) = 4,042.54, P < 0.001, η2p = 0.666] and nonpartisan
proportional policy [M = 0.43; B = 0.59, F(1, 2,400) = 68.10, P < experts (M = 1.42), toward whom they reported more positive
0.001, η2p = 0.028]. This difference was larger for Republicans affect than toward ingroup political elites [B ¼ 0.43, F(1, 2,026) =
(M 2difference = 1.07) than for Democrats [Mdifference = 0.30; B = 0.77, 131.81, P < 0.001, ηp = 0.061; Fig. 3B]
†. A one-way ANOVA on
F(1, 2,400) = 29.39, P < 0.001, η2p = 0.012], although there was no affect revealed a highly significant effect of target [F(2, 4,046) =
overall difference between Democrats’ and Republicans’ policy sup-
2 4,130.40, P < 0.001, η
2
p = 0.671]. In a multiple linear regression,port [B = 0.01, F(1, 2,400) = 0.03, P = 0.856, ηp < 0.001; Fig. 3A].
As predicted, Democratic respondents supported policies pro- respondents’ support for a COVID-19 vaccine distribution policy
posed by Joe Biden and Democratic policymakers (M = 1.13) was positively predicted by their feelings toward the group
more than policies from Donald Trump and Republican policy- proposing the policy [B = 0.36, F(1, 2,214) = 299.74, P < 0.001,
2
makers [M = –0.15; B = –1.26, F(1, 2,400) = 82.30, P < 0.001, η2 ηp = 0.119], controlling for political cue manipulation, respon-p
= 0.033], and Republicans supported Republican policies (M = dent partisan identification, and policy emphasis. These results
1.36) more than Democratic policies [M = –0.05; B ¼ 1.34, F(1, demonstrate that the same processes that polarize public atti-
2,400) = 84.07, P < 0.001, η2 tudes toward COVID-19 mitigation policies also influencedp = 0.034]. These polarized patterns
produced an interaction between respondent partisan identifica- Americans’ support for policies to combat COVID-19 globally
tion and whether the policy was proposed by Democratic or through international vaccine distribution.
Republican politicians [B ¼ 2.60, F(1, 2,400) = 166.33, P <
0.001, η2p = 0.065]. Independents’ support did not differ between Discussion
Democratic or Republican cues conditions [B ¼ –0.12, F(1, COVID-19 laid bare both the difficulty and importance of
2,400) = 0.30, P = 0.586, η2 < 0.001]. establishing and maintaining broad public support for policiesp
As in the first experiment, policies from nonpartisan experts to address the pandemic. The present findings suggest that the
and a bipartisan coalition enjoyed greater overall support (M =
0.96) than did policies from either Democratic or Republican † Independents were excluded from the analysis of affective polarization of ingroups and
elites [M = 0.49; B ¼ 0.42, F(1, 2,400) = 35.32, P < 0.001, η2p = outgroups.
Flores et al. PNAS j 5 of 7
Politicians polarize and experts depolarize public support for COVID-19 https://doi.org/10.1073/pnas.2117543119
management policies across countries
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Table 2. Multiple linear regression predicting respondents’ COVID-19 policy support from affect toward the group proposing the
policy and contrast-coded predictors for political cues, respondent partisan identification, and policy emphasis, including deviation
coding for country
Statistic
Predictor B 95% CI SE F P
Outgroup political cues (without affect and controls in the model)
Outgroup vs. ingroup 0.32 0.23, 0.40 0.044 52.01 <0.001
Ingroup/outgroup vs. bipartisan/expert 0.23 0.17, 0.29 0.031 56.13 <0.001
Bipartisan vs. expert 0.05 0.04, 0.13 0.043 1.30 0.255
Outgroup political cues (including affect and controls in the model)
Outgroup vs. ingroup 0.17 0.27, –0.07 0.049 12.01 <0.001
Ingroup/outgroup vs. bipartisan/expert 0.03 0.04, 0.08 0.031 0.31 0.576
Bipartisan vs. expert 0.33 0.42, –0.24 0.046 50.61 <0.001
Affective measure
Affect toward proposer 0.22 0.19, 0.24 0.012 306.43 <0.001
Respondent partisan identification
Liberal vs. conservative 0.05 0.11, 0.01 0.030 2.55 0.110
Policy emphasis
Public health vs. economic 0.74 0.80, –0.69 0.029 680.84 <0.001
foregrounding of political elites triggered affective polarization In an interconnected world, shared threats of pandemics and
and polarized public opinion to COVID-19 policies, not only in other international crises will be increasingly common (49, 50).
the United States but across a diverse range of countries. These Partisan elites create barriers to combatting these threats by
polarizing effects occurred for COVID-19 containment policies, polarizing public support for effective policies. These barriers
as well as, in the United States, policies about international can be overcome by foregrounding bipartisan coalitions and
COVID-19 vaccine distribution. Policies backed by bipartisan nonpartisan experts in public health communication.
coalitions and nonpartisan experts precluded these polarizing
effects by avoiding association only with outgroups. Materials and Methods
The similarity of findings across these politically and culturally The Institutional Review Board at the University of Colorado categorized the
diverse countries, as well as across policy subjects in the United study as exempt (Protocol 20-0197). Respondents provided informed consent
States, suggests that the influence of partisan elite cues and affec- before completing the study. All materials, data, and analysis scripts are avail-
tive polarization are neither confined to the United States nor a able on OSF, housed within the Political Cues folder: https://osf.io/ewr7g/.
function of a specific policy domain. Social-behavioral scientists
should therefore look beyond US-centric processes such as its Respondents. In the main experiment, we surveyed diverse national samples
two-party system, ideological sorting, and uniquely polarized (n = 12,955) between 3 and 20 August 2020, from Brazil (n = 1,500), Israel
media (27–29) that do not readily explain polarizing effects in (n = 1,958), Italy (n = 1,586), South Korea (n = 1,484), Sweden (n = 1,589),
other countries. Although there may be some exceptional ele- the United Kingdom (n = 1,520), and the United States (n = 3,318). Samples
were drawn from online panels based in each of the seven countries. Sampling
ments of political sectarianism (9) in the United States, the pre-
quotas for age and gender were used to select respondents and respondents
sent results imply more widespread social, cognitive, and affective were financially compensated for their participation, except in the Swedish
explanations for the polarizing influence of political elites. sample. Surveys were completed online and administered in each country’s
The results provide suggestive evidence that affective polariza- official or national language. Surveys were adapted from English by the
tion contributes to the polarizing effects of partisan elites. Impor- authors who are fluent in both English and the target language and who
tantly, measuring affective polarization before policy stances have expertise in the cultural and political contexts of each country (see OSF
ensures that descriptions of policies could not have influenced File 1 for more information on sampling method by country and sample
affect (8). Although it is possible that measuring affective polari- descriptive statistics). In the follow-up experiment, we surveyed 2,463 respond-
zation exacerbated the effects of political elite cues by priming ents in the United States who had participated in the main experiment (of
intergroup animosity, studies in the United States have demon- 3,346 eligible US respondents, a 73.6% recontact rate) from 30 October to
15 November 2020.‡
strated comparably large effects of political cues without measur-
ing affective polarization (19–21). Future work could expand on Policy Emphasis Manipulation. In the main experiment, respondents were ran-
these findings by experimentally manipulating affect orthogonal domly assigned to evaluate one of two policies to manage the COVID-19 pan-
to political elite cues to better establish affect’s causal role. demic. Both policies specified social distancing and lockdowns. The public
Future work might also expand the number and range of coun- health policy emphasized public health goals, which included more severe
tries in a design with similar policy contexts and proposals. restrictions and an 18-mo lockdown that focused “primarily on keeping
Although this study included a range of countries, four of the seven COVID-19 case numbers down.” The economic policy emphasized “recovery
were individualistic, Western countries. Broader representation of the economy as much as possible while preventing a resurgence in COVID-
of non-Western, less-individualistic, less-wealthy countries would 19 cases,”with fewer restrictions and a 6-mo lockdown.
afford stronger tests of the generality of polarizing phenomena. In the follow-up experiment, respondents were randomly assigned to eval-
uate one of two policies regarding international vaccine distribution. The
In demonstrating that expert sponsored policies are depolarized
American prioritization policy stated that because the United States had led
and widely supported, the present results stress the importance of vaccine development it “should be able to distribute vaccines to its people
maintaining trust in nonpartisan experts. The politicization of before sending vaccines to other countries.” The internationally proportional
experts undermines their broad credibility (47, 48), which has policy stated that “other countries should not be punished for not having the
begun to erode among conservatives worldwide (35, 36). Preserv-
ing scientists’ and public health experts’ nonpartisan status enables ‡By October 2020, both the Pfizer-BioNTec and Moderna vaccines had entered phase III
them to uphold their effectiveness in providing crucial guidance efficacy trials, but neither vaccine had been issued Emergency Use Authorization by the
during crises like the COVID-19 pandemic. FDA yet.
6 of 7 j PNAS Flores et al.
https://doi.org/10.1073/pnas.2117543119 Politicians polarize and experts depolarize public support for COVID-19
management policies across countries
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means to fund vaccine trials” and that “vaccines should be distributed propor- (51). We used these responses to categorize respondents, including leaners, as
tionally to country population size until 20% of each population is protected.” Liberal, Conservative, or Centrist.
Affective polarization measures were collected before the presenta-
Political Cues Manipulation. For both experiments, we crossed the policy tion of the COVID-19 policy and the political cues manipulation. To mea-
emphasis manipulation with the political identity of the policy’s proposal sure affective polarization, respondents reported their affect toward
group. Respondents read a policy proposed by one of four partisan proposal three groups: liberal elites, conservative elites, and experts. They reported
groups: liberal elites, conservative elites, a bipartisan coalition of liberal and trust (3 = strongly distrust, +3 = strongly trust), liking (3 = strongly dislike,
conservative elites, or relevant experts including the World Health Organiza- +3 = strongly like), and temperature (3 = very cold, +3 = very warm).
tion. Liberal and conservative elites were defined within each country, for We averaged these responses into a composite measure for each target
example, Democrats versus Republicans in the United States, politicians from (α = 0.90, 0.92, and 0.87, respectively).
the progressive opposition versus the conservative government in Brazil, and
Social Democratic versus Moderate politicians in Sweden. Specific politicians Data Analysis. Analyses were conducted using R version 4.0.2. We analyzed
were named among party elites in all countries except in Israel and South data with multiple linear regressions using contrast-coded predictors, their
Korea, where the framing effects were comparable to the overall effect (see interactions, and fixed effect deviation coding to compare each country to the
SI Appendix, Table S1 for list of political groups by country; see OSF File 2 for overall mean (see SI Appendix, Table S3 for contrast codes). Degrees of free-
the full text of US policy stimuli). dom vary across analyses due tomissing data.
Measures. Respondents indicated howmuch they supported the overall policy Data Availability. Survey data have been deposited in OSF (https://osf.io/
and four specific policy components: social distancing, workplace regulations, ewr7g/?view_only).
contact tracing, and travel regulations (3 = strongly oppose, +3 = strongly
support), which we averaged into an index of policy support (α = 0.89). ACKNOWLEDGMENTS. Two reviewers provided insightful comments on the
Respondents indicated their partisan identification with the relevant politi- manuscript. NSF Division of Social and Economic Sciences Grant 2029183 sup-
cal groups in their country using two branched questions as in previous papers ported this research.
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Flores et al. PNAS j 7 of 7
Politicians polarize and experts depolarize public support for COVID-19 https://doi.org/10.1073/pnas.2117543119
management policies across countries
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