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Full paper xxxx This investigated if and how public understanding of the scientific S. van der Linden,* A. Leiserowitz, consensus on human-caused climate S. Rosenthal, E. Maibach...... 1600008 change can be protected (“inoculated”) against influential misinformation. Inoculating the Public against Results from a large survey Misinformation about indicate that public of the scientific consensus can be effectively inoculated against misinformation across the political spectrum. Full paper

- - - [28] 1600008 In a [16–23] (1 of 7) Furthermore, Furthermore, For example, For [8] [16,30] [10,12,13] These campaigns have www.global-challenges.com [9,10] particularly because doing so is wileyonlinelibrary.com and limited deeper societal engage- [25–27] [11] Polarization can be amplified when can be amplified when Polarization For example, a large body of research For Thus, in the face of political polariza- As such, adopting consensus beliefs can not only successfully undermined public not only successfully undermined public understanding of the degree of scientific agreement on climate change, they have - also increased existing political polariza tion ideologically motivated, vested-interest ideologically motivated, of Doubt” groups known as “Merchants “disinfor influential orchestrated have mation campaigns” in which they pub- in which mation campaigns” on licly dispute the scientific consensus human-caused including issues, various climate change. the inherent of itself the inherent uncertainty on the existence of is used to cast doubt a scientific consensus. 1.1. Perceived Scientific Consensus as a 1.1. Perceived Scientific Gateway One promising way to counteract the to highlight the of science is politicization ment with the issue. [31] [29] [8,14,15] Accordingly, research has found that in the absence Accordingly, [24] In fact, people prefer to take cues from the combined judgment of multiple experts. research finds that people’s of expert consensus research finds that people’s (even when correct) is easily undermined by anecdotal evidence actual the distort can which of both balance,” “false and weight of evidence. often socially adaptive, as “consensus implies correctness.” as “consensus socially adaptive, often complex and uncertain world, people often look to experts for look to experts for complex and uncertain world, people often guidance. tion, effectively communicating with the public about the sci- communicating tion, effectively entific consensus requires knowledge about; (a) the way in which people attend to, process, and organize new information strong scientific consensus about an issue when a scientific an issue when a scientific consensus about strong scientific consensus exists. mation by triggering a motivation for (some) citizens to dis- miss otherwise credible scientific evidence. improve judgment-accuracy and reduce the cost of learning by and reduce the cost of learning improve judgment-accuracy condensing complex science into a simple fact (e.g., “97% of climate have concluded that human-caused global same time, the politicization the At warming is happening”). infor of consensus undermine the influence of science can of motivation to cognitively elaborate on a message, people of motivation to cognitively elaborate on tend to heuristically rely on consensus cues to form judgments about sociopolitical issues, has found that “perceived scientific agreement” is a key deter has found that “perceived scientific agreement” change. climate on opinion minant of the public’s the [1–4] [7] This is problematic because [5,6] 2016 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim GmbH & Co. 2016 The Authors. Published by WILEY-VCH Verlag © 2017, 1600008

www.advancedsciencenews.com Effectively addressing climate change requires significant changes in indi- climate change requires significant Effectively addressing of in light Yet, human behavior and decision-making. vidual and collective of vested- of (climate) science, and the attempts the increasing politicization climate change the scientific consensus on interest groups to undermine ways to effec- campaigns,” identifying through organized “disinformation spectrum public about the issue across the political tively engage with the research suggests that one promising has proven difficult. A growing body of is to convey the high level way to counteract the politicization of science among experts about the reality of of normative agreement (“consensus”) much prior research examining public human-caused climate change. Yet, change has done so under condi- opinion dynamics in the context of climate - no research to date has exam Moreover, tions with limited external validity. spread of influential misinformation ined how to protect the public from the bridges this divide by exploring about climate change. The current research cues in a polarized information how people evaluate and process consensus is provided that it is possible to pre- evidence environment. Furthermore, about climate change against emptively protect (“inoculate”) public attitudes real-world misinformation. This is an open access article under the terms of the Creative Commons Commons This is an open access article under the terms of the Creative Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. general public has become increasingly polarized on the issue, general public has become increasingly polarized particularly in the United States. global challenges Although numerous independent assessments have found that Although numerous independent assessments con- a near-unanimous the has reached change, sensus on the reality of human-caused climate 1. Introduction addressing global climate change will require large-scale changes in human behavior and decision-making.

Climate Change Climate Maibach Seth Rosenthal, and Edward Linden,* Anthony Leiserowitz, Sander van der Inoculating the Public against Misinformation about about Misinformation Public against the Inoculating DOI: 10.1002/gch2.201600008 Dr. S. van der Linden Dr. Department of Psychology University of Cambridge UK CB2 3EB, UK Cambridge, E-mail: [email protected] S. Rosenthal A. Leiserowitz, Dr. Dr. Program on Climate Change Yale University Yale New Haven, CT 06511, USA Prof. E. Maibach for Climate Change Communication Center George Mason University 22030, USA VA Fairfax, Full paper 1600008 remains unclear. tions, itsefficacy inthepresenceofreal-worldmisinformation tific agreementhasbeenfoundeffective understylizedcondi- ical “contagion.” misinformation spreadsthrough apopulationasmetaphor researchers haverecentlyconceptualized theprocessbywhich by, orcanbeprotectedagainst,“sticky” misinformation. Infact, about the scientific consensus on climate change are affected no researchtodatehasexaminedifandhowpublicbeliefs opportunity toexaminemotivatedcognition.To ourknowledge, the pairingofconflictinginformationalcuesisanexplicit cascading effect on other personal beliefs and behaviors. debiasing people’s perceptionofthenormoften hasapositive Indeed, muchsocial–psychologicalresearchhasshownthat to smallyetimportantchangesinotherkeypersonalbeliefs. agreement amonginfluentialreferents(e.g.,experts)canlead ple’s subjective perception and the actual of level of normative action. pening, human-caused,andaseriousissuethatrequirespublic other keybeliefs,such as the that climate change is hap- perception ofthescientificconsensus,whichinturninfluences issues, suchasvaccinesandclimatechange,canshift public nicating thedegreeofscientificagreementoncontestedsocietal cues atthesametime. More generally, peopleoften processconflictinginformational Inoculation Theory 1.2. Countering theSpreadand InfluenceofMisinformation: deeply held ideological worldviews. tion andrejectevidencethatrunscontrarytopriorbeliefsor soning canlead(some)peopletoselectivelyprocessinforma- instances inwhichconfirmationbiasandmotivatedrea- change. in whichpeopleformjudgmentsandopinionsaboutclimate and (b)thestructuralnatureofinformationenvironment more mixedevidencehasalsobeennoted. polarizing worldviews Yet, althoughhighlightingscientificconsensuscanneutralize is often describedasanidea, behavior, orstylethatspreads ideological spectrum,eitherdirectlyorindirectly. and acceptanceofanthropogenicclimatechangeacrossthe climate changeishappeningcanincreaseperceivedconsensus the factthatmostscientistsareconvincedhuman-caused judgment cues.Accordingly, manystudiesfindthatconveying believe (i.e.,“metacognitions”) often serveasinformational the cultural cognition thesis, polarization. ment aboutcontestedsocietalissueswillonlyincreaseattitude tural cognitionthesispredictsthatconveyingscientificagree- Linden et al. ticular, thegatewaybeliefmodel(GBM) developed byvan der ment. people canorientthemselvestowardscienceandtheenviron- assimilation ofinformation is justoneofmanywaysbywhich www.global-challenges.com On one hand, research has offered ample evidence for People’s subjectiveperceptionsaboutwhatothergroups On theotherhand,scholarshavequestionedvalidityof (2 of7) [40] [7,41] Asubstantialbodyofresearchhasfoundthatcommu- [37] [7] suggests that reducing the “gap” between peo- [51] wileyonlinelibrary.com [49,50] Acloselyrelatedtermisa“meme,” which Yet, evaluatingthisisimportantbecause [19,44] [48] Thus,althoughhighlightingscien- andreducemotivatedreasoning, [38,39] especially because the biased [32–36] © 2016TheAuthors.Published byWILEY-VCHVerlag GmbH&Co. KGaA,Weinheim For example, the cul- [47] [19,42–44] Inpar [45,46] [8] - -

simple “cultural truisms” canbemaintained. research hasprimarilyexaminedhowpositiveattitudestoward context ofclimatechange.Moreover, priorinoculationtheory memes aresometimesreferredtoas“thoughtcontagions.” from persontowithinaculture. has demonstrateditsefficacy counterarguments. pre-emptively highlighting false claims and refuting potential ferent experimentalconditions isprovidedinTable six different experimentalconditions. Anoverviewofthedif subject) estimateofthescientific consensusacross(between) a mixeddesignthatcompared aparticipant’s pre–post(within- Information formoreinformation aboutMturk).We employed against suchmisinformation (see Part BintheSupporting Turk (Mturk) to test whether it is possible to “inoculate” people large anddiversesample(N we conductedarandomizedonlinesurveyexperimentusing a termessages” usedbyclimatechangeopponents.InStudy2, was toidentifythemostinfluentialandrepresentative “coun- on human-causedclimatechange.ThepurposeofStudy 1 eral misinformationstatementsaboutthescientificconsensus probability sampleoftheUSpopulation(N tions. Inthefirststudy, weusedanationallyrepresentative Two studieswereconductedtoanswertheseresearchques- 2. Method unking.” refuted in a process called “refutational pre-emption” or “preb- ened) examplesofthatinformationarepresentedanddirectly their existing beliefs or behaviors. Then, one or more (weak- people thattheymaybeexposedtoinformationchallenges follows asimilarlogic:Athreatisintroducedbyforewarning The social–psychologicaltheoryofattitudinalinoculation but notsostrongastooverwhelmthebody’s immunesystem. enough totriggeraresponse(i.e.,theproductionofantibodies), someone toaweakenedversionofthevirus(avaccine)—strong medicine, resistancetoaviruscanbeconferredbyexposing slowed through a process known as attitudinal inoculation. In paigning, vated reasoning. pre-existing (positive)attitudesaswellhelpcounteractmoti- hypothesize that the process of inoculation will indeed protect (influential) misinformation?Drawingonpriorresearch,we attitudes aboutthedegreeofscientificconsensusagainst mate change?Andifso,(2)isitpossibleto“inoculate” public tive effect ofcommunicatingthescientificconsensusoncli- (1) doesthepresenceofmisinformation“negate” theposi- this studyaddressesthefollowingtwokeyresearchquestions: strongly differing pre-existing(political)attitudes.Accordingly, many issues,includingclimatechange,wherepeoplehave to another. mate )thatistransmitted(replicated)fromonemind curate mentalbelief(e.g.,thereisnoconsensusamongcli- global warming,afalsememecanbethoughtofasaninac- texts, mostnotablyintheareasofhealth Although alargebodyofresearchoninoculationtheory The rateofculturaltransmission,orinfection,maybe [14] [59] [54] Inshort,attitudinalresistanceisconferredby inoculationtheoryhasnotbeentestedinthe Because of their socially infectious nature, (false) Becauseoftheirsociallyinfectiousnature,(false) = 2167)fromAmazonMechanical [57] inavarietyofappliedcon- www.advancedsciencenews.com global challenges2017 , 1600008 [52,53] [58] andpoliticalcam- = 1000)totestsev- Inthecontextof [60] Yet, thereare 1. [55] [56] -

Full paper

- 1600008 (3 of 7) 51 38 32 32 17.7 Census www.global-challenges.com 1. As expected, no mean- 56 50 37 17.3 25–44 wileyonlinelibrary.com (N = 2167) 0.35). The consensus-treatment (CT) = 0.35). The consensus-treatment

3 and Figure diff Sample characteristics. . . A description of the MTurk procedure and platform is platform and procedure MTurk of the description 2. A The design of the experiment follows a linear-additive format The design of the experiment follows a linear-additive post) and (pre respondent’s a is variable dependent main The Sample Age 18–65+ (modal bracket) or Education (% college degree higher) Region (% Northeast) Party affiliation (% Democrat) Demographic characteristics Demographic Gender (% female) ingful pre–post change in perceived consensus was observed in the control group (M Table 2 - census estimates. Age (median). Political party affilia Note: US population 2013 tion estimate by Pew (2013). 3. Results All of the hypotheses were fully supported by the data. Descrip- agreement scientific in perceived differences within-subject tive are reported in Table debunk the Oregon Petition specifically (e.g., by highlighting specifically (e.g., by highlighting Petition debunk the Oregon are fraudulent, including Charles that some of the signatories that fewer than 1% Darwin and members of the Spice Girls, atmospheric/climate of the signatories have a background in science, etc.). countermessage- and consensus- the both in 1)—i.e., (Table the relevant message only conditions, respondents only read respondents in isolation. In the general inoculation condition, by a general inoc- first read the consensus statement, followed In the ulation, before being exposed to the countermessage. were first shown detailed inoculation condition, respondents general inoculation the consensus message, followed by the message, before being and then the more detailed inoculation design allowed us to exposed to the countermessage. This inoculation strategies. assess the marginal benefit of the (two) in Study 2 is provided A full description of all treatments used Information. in part B of the Supporting agreement on human- estimate of the current level of scientific subjects were caused climate change (0%–100%). In addition, estimate, how likely also asked how certain they are about their they whether is happening, change climate that is think it they they worry about the believe it is human-caused, how much about less or more doing be should people whether and issue, experiment, disguise the true purpose of the climate change. To participants were told that they would randomly be asked about 1 out of 20 possible media topics (the topic was always the same). All subjects were presented with the same question set (post) the treatments were administered. before (pre) and after efficacy the verify to included also was check manipulation A An overview of the sample character of the treatment effects. istics (and census data for comparison purposes) is provided in Table Information. B of the Supporting provided in Part - - CM) CM) —because this [62] To ensure a representative To [44] 2016 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim GmbH & Co. 2016 The Authors. Published by WILEY-VCH Verlag © general inoculation followed by countermessage (In1 | general inoculation followed detailed inoculation followed by countermessage (In2 | detailed inoculation followed which hosts a website claiming that; “over 31 000 which hosts a website claiming that; “over 2017, 1600008 [61] Overview of experimental conditions. Overview of . Prior research has found that the scientific consensus is Study 1 investigated which countermessage was most influ- most was countermessage which investigated 1 Study In short, we hypothesized that communicating the scientificIn short, we hypothesized www.advancedsciencenews.com Experimental treatment conditions Experimental 6. Consensus-treatment + 6. Consensus-treatment 1. Control group 1. Control chart”) treatment (CT) (“pie 2. Consensus (CM) 3. Countermessage by countermessage (CT | CM) followed 4. Consensus-treatment + 5. Consensus-treatment American scientists have signed a petition stating that there is American scientists have signed a petition of carbon dioxide no scientific evidence that the human release heating of the will, in the foreseeable future, cause catastrophic exact copy of the petition was used as atmosphere.” An Earth’s all identifying source- the main countermessage in Study 2, but confounding effects information was redacted to prevent between the source and the message. in the form of a pie chart stating: communicated effectively “97% of climate scientists have concluded that human-caused climate change is happening.” ceived scientific agreement (condition 2), whereas the coun- the whereas 2), (condition agreement scientific ceived termessage (by itself) (condition 3). would have a negative impact that the presence of counterinformation also hypothesized We of the consensus message would diminish the general efficacy - as a direct test of inoculation, we hypothe (condition 4). Finally, inoculation messagesized that both a general and more specific the misinforma- would protect the consensus-treatment against in the control tion statement (conditions 5 and 6). Participants puzzle. group (condition 1) solved a neutral word common statements were ential with the American public. Six Information for a full A in the Supporting tested (see Part each statement description of the study). Respondents ranked Out of all on two dimensions: familiarity and persuasiveness. with and convinced statements, respondents were most familiar on human-caused by the argument that “there is no consensus on a real disinfor climate change.” This argument was based Pro- Petition mation campaign (“The Oregon Global Warming ject,” 2007) consensus (by itself)influence on per would have a positive graphic has frequently been featured in the media. The inocu- graphic has frequently of (a) warning components: of two consisted messages lation prior beliefs and attitudes an impending threat/attack on one’s and (b) a pre-emptive refutation (cogni- component) (affective general version, respondents tive component). In the shorter, were first warned: “some politically motivated groups use misleading tactics to try to convince the public that there is a lot of disagreement among scientists.” This claim was then debunked by reiterating that scientific research has found that among climate scientists, there is virtually no disagreement that more spe- humans are causing climate change. In the longer, cific inoculation condition, additional arguments were added to global challenges Table 1 study design in which the messages shown to participants reflect real-world content, we mimicked the design of the pie chart used by the “Consensus Project” Full paper 1600008 sage (CM) had a substantial negative influence ( presence ofcounterinformation( much ofthepositiveeffect oftheconsensusmessagein inoculation interventionswereeachsuccessfulinpreserving hypothesized, thegeneral(In1 ( alone elicitedalargeincreaseinperceivedscientificagreement the controlgroup( There was one exception, as expected, the difference between differences forallthepreviouslystatedcomparisons( cant Difference (HSD)testindicatedsignificantbetween-group the adjustedmarginalmeansusingTukey HonestSignifi (MSE) the treatment groups, covariate. TheANCOVA revealedasignificantmaineffect for the post-test as the dependent variable and the pretest as the cant, ananalysisofcovariance(ANCOVA) wasconductedwith effect, respectively). one-third and two-thirds of the initial consensus-treatment consensus-treatment wasnegatedcompletely( sages sequentially(CT when presentedonitsown.Whenparticipantsviewedthemes consensus by treatment group. Note: CT Figure 1. Error barsrepresent95%confidence intervals. countermessage, In1 www.global-challenges.com Table 3 Table Consensus-treatment (CT)( Control group( CT CT Consensus-treatment (CT) Countermessage (CM)( Treatment conditions M To testwhetherthesedifferences arestatisticallysignifi + + diff detailedinoculation generalinoculation

(4 of7) = .

= 19.72).Incontrast,the(misinformation)countermes

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2016TheAuthors.Published byWILEY-VCHVerlag GmbH&Co. KGaA,Weinheim [%] (pretestmean) = 6.47and12.71—or = detailed inoculation. 70.58 73.29 73.48 72.04 72.18 71.23 M = diff M 0.36)andthe

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[%] (post-testmean) ceived scientificconsensusbypoliticalpartyaffiliation. 4 Table presence oftheconsensus-treatment( it was significantly more convincing than when viewed in the ticipants who viewed the counterinformation by itself thought “neutralizing” (CT ( (descriptively) for Republicans ( effect oftheconsensus-onlytreatmentissomewhatlarger affiliation. similar proportionsofthetreatment-effect across political party and specificinoculationconditionsbothsuccessfullypreserve positive effect oftheconsensus-treatmentwhilegeneral has anegativeeffect, sequentialmessagingneutralizesthe own elicitsthegreatestchange,countermessagebyitself similar acrosspartylines,i.e.,theconsensus-treatmentonits identification ( were examinedforeachtreatmentconditionbypoliticalparty t t the consensus message in the presence of counterinformation sage wassignificantlymoreconvincingthanthosewhoviewed ents whoonlyviewedtheconsensus-treatmentthoughtmes convincing theyfoundtheexperimentaltreatments.Respond ipants wereasked,usingaseven-pointscale,toindicatehow the consistencyofresults.At theendofsurvey, partic significant. ( rate thanthosewhowerelessconvinced( adjusted theirestimateofthescientificconsensusatahigher found theconsensus-treatmentmoreconvincing(mediansplit) CT Consensus-treatment (CT) Countermessage (CM) Consensus-treatment (CT) Control group CT Treatment conditions (1526) (1037) M x + Yet, twoobserveddifferences arenoteworthy. First, the Next, within-subjectdifferences inperceivedconsensus A numberofmanipulationcheckswereperformedtoassess + = diff generalinoculation detailedinoculation 5.11 90.30 72.53 83.94 79.76 72.99 63.05

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CM | 4 ), CM ). Onthewhole,patternisstrikingly t Difference (post-pretest) (1237) (standard error) Democrat − − 19.72 (1.17) 12.71 (1.17) ( 0.35 (0.36) 6.47 (1.32) n 0.51 (1.39) 8.99 (1.31) − 15.78 11.08

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= 23.00) and Independents = p global challenges Independent 0.51

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Other [70] [69] (5 of 7) Moreover, this Moreover, Second, this research Second, this www.global-challenges.com [48,50,67,68] For example, simple corrections For [7,19,38,43,44,47] wileyonlinelibrary.com [33] [7,17] Similarly, we find that when the Similarly, [47] Yet, “true” polarization in response attitude polarization “true” Yet, [37] Results indicate that the positive influence of the “consensus the positive influence of the Results indicate that More importantly, both inoculation messages proved effec More importantly, Some scholars have argued that because people sometimesSome scholars have argued that because This is not to say that the motivated processing of political This is not to say that the motivated processing sensus information had been presented at all. In other words, the countermessage who only saw respondents Republican decreased their estimate of the scientific consensus more than Republican respondents who saw both messages. Thus, we find no evidence that conveying strong normative agreement among with potentially skeptical audiences. experts “backfires” consensus and countermessages were presented sequentially, consensus and countermessages were presented sequentially, Republican respondents were, on average, indeed more likely in their treatment more heavily to weigh the “no consensus” Yet, it is subsequent judgment of the scientific consensus. important to note that even in this case, highlighting scientific observed the of magnitude the as beneficial, still is agreement (or at the among Republicans is actually less “negative effect” from what it would have been if no con very least, no different) further extends these findings by presenting information about by presenting information these findings further extends information environ “contested” in a politically the consensus that there is petition claiming is, countered by a real ment, that As change. climate human-caused on consensus scientific no the criticism that prior “do such, we help address the real-world dynamics of opinion forma not realistically model [49], p. 16). (ref. change dispute” tion relevant to the climate alongside such is largely negated when presented message” of consensus in evaluating the efficacy misinformation. Thus, should recognize the potent role of mis messaging, scholars real-world attempts to convey information in undermining Third, the current study also found the scientific consensus. was preserved (up to consensus-effect that much of the initial importantly, which, messages, by the inoculation two-thirds) Accord the political spectrum. across proved equally effective is a promising approach to protect public “inoculation” ingly, that human- understanding of the extant scientific consensus research as prior which, is happening, change climate caused cognition to other has shown, acts as an important “gateway” keys beliefs about the issue. recent research has suggested that communicating the scien tific consensus on climate change may backfire among strong endorsers. “free-market” can backfire among the targeted ideological group. can backfire among the targeted ideological tive in protecting the positive effect of the consensus message tive in protecting the positive effect engage in “identity-protective motivated reasoning,” highlightingengage in “identity-protective motivated reasoning,” exacerbate existing atti scientific consensus will only cause or tude polarization. to mixed evidence is relatively infrequent (refs. [64–66] and recentto mixed evidence is relatively infrequent (refs. on climate changeresearch suggests that political polarization to partisan mediais more likely the result of selective exposure rather than motivated reasoning alone. human-caused climate change. human-caused study finds no support for the hypothesis that inoculating peoplestudy finds no support for the hypothesis are consensus backfires among those who scientific about the about climate changeideologically predisposed to be skeptical and consistent with(e.g., Republicans), which is both promising In fact,[60]). ref. see (e.g., theory research on inoculation other direction by testing itswe extend inoculation research in a novel in the context of a highly politicized issue. efficacy information does not occur.

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0.41, F = 0.10). Finally, the treatments did not have notable main 0.10). Finally, countermessage, In1 0.05), the consensus-message (by itself)the consensus-message 0.05), small positivehad a = = A main effect was also found for belief , was also found for belief certainty, A main effect <

p www.advancedsciencenews.com effects on other key beliefs about climate change—with the excep on other key beliefs effects tion of normative support for public action, MSE SE lican respondents ( Independents ( initial effect was preserved in both the general and more detailed was preserved initial effect inoculation conditions ( in the presence of counterinformation. As expected, much of the Main results are presented in Table 4 and results are presented in Table Main 52.94, MSE tion. In particular, our results point to three important conclu tion. In particular, support consistent with prior work, we find strong sions. First, the scientific consensus of communicating for the efficacy on 4. Discussion attitudes about climate change public that finds This study against influential misinforma “inoculated” can be effectively global challenges the consensus-treatment for both Democrats ( the consensus-treatment for both Democrats while the presence of misinformation “neutralizes” the effect of the effect while the presence of misinformation “neutralizes” main effect ( main effect ( counterinformation and control groups ( control counterinformation and the consensus-treatment (by itself) increased belief certainty (1–7 scale) by ( the Tukey Honest Significant Difference (HSD) test indicated that Difference Significant Honest the Tukey conditions significantlythe consensus-treatment and inoculation to thebelief certainty of consensus estimates compared increased party, party, viewed the consensus message followed by the counterinfor viewed the consensus message followed revealed a small but signifi an ANCOVA mation. Accordingly, and political cant interaction between the treatment conditions only Republicans reduced their consensus estimates when they only Republicans reduced their consensus tion. Error bars represent 95% confidence intervals. Figure 2. CT consensus by political party affiliation. Note: CM Full paper 1600008 the scientificconsensus(BarsIVand V, In1| helps promoteandprotect(“inoculate”) publicattitudesabout about politicallymotivatedattemptstospreadmisinformation ( the public’s perceptionofthelevelscientificagreement the presentationofmisinformationsignificantlyundermines in theabsenceofanycuesaboutactuallevelconsensus, lighting normativeexpertagreement(BarIII,CT| of ascientificconsensusneutralizesthepositiveeffect ofhigh- the introductionof(mis)informationcontestingexistence by about20percentagepoints(BarI,CT-Only). Importantly, nificantly increasespublicperceptionoftheexpertconsensus the scientificconsensusonhuman-causedclimatechangesig- In alargeexperiment(N 5. Conclusion ment strategy. change, canbeaneffective anddepolarizingpublicengage - among expertsabouttherealityofhuman-causedclimate municating asocialfact,suchasthehighlevelofagreement findings addtoagrowingbodyofresearchreportingthatcom- paigns— topre-emptivelyrefutesuchattempts.Inshort,these a basicexplanationaboutthenatureofdisinformationcam- audiences should be provided with the “cognitive repertoire”— seek tounderminethefindingsofclimatescience.Inaddition, the publicthatpoliticallyoreconomicallymotivatedactorsmay change shouldbeaccompanied by informationthat forewarns municating thescientificconsensusonhuman-causedclimate reduce directionalmotivatedreasoning(e.g.,seeref.[8]). people pre-emptively of counterattitudinal messages can help with otherrecentresearch,whichhasalsofoundthatwarning sions ofclimatescience.Moreover, theseresultsareconsistent Democrats alikeinadirectionconsistentwiththeconclu- and shifted theopinionsofRepublicans,Independents,and the AndlingerCenter forEnergy andtheEnvironmentfortheirgenerous the Environment,11thHourFoundation, theEnergyFoundation, and The authorsacknowledgetheGrantham Foundation fortheProtectionof Acknowledgements from theauthor. Supporting InformationisavailablefromtheWileyOnlineLibrary or Supporting Information test andextendthesefindingsinreal-world(field)settings. ment. Thus,welookforwardtoandencouragefutureresearch to simulatethestructureofanindividual’s informationenviron- a representativedesign,laboratoryresearchislimitedinitsability research isneeded.Second,whilegreatcarewastakentoensure do persistovertime(e.g.,ref.[71]),althoughmorelongitudinal has indicatedthatthepositiveeffects ofattitudinalinoculation of theinoculationmessages.However, otherrecentresearch we were unable to assess the rate of decay (if any) of the effect www.global-challenges.com − 9 points;BarII,CM).Finally, pre-emptivelywarningpeople Practically, these findings suggest that, when possible, com- Finally, thisstudyisofcoursenotwithoutlimitations.First, (6 of7) [7,19,43,44,47] wileyonlinelibrary.com

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