Disagreement and motivated reasoning

Bjørn Hallsson defends his PhD thesis.

 

The dissertation explores the impact of motivated reasoning, a tendency for reasoning to proceed with the goal of construing evidence in ways that are supportive of a desired conclusion, for normative discussions in the epistemology of disagreement and political philosophy. The introduction provides a brief overview of the psychology of motivated reasoning and its consequences. One of these is belief polarization, a tendency for the beliefs of people who initially disagree to move toward the extremes after the persons view the same body of evidence.

Another is that deliberation in groups with internal disagreement is an effective means of epistemic improvement. The introduction also provides overviews of the epistemology of disagreement and the role of disagreement for political legitimacy, and details the contributions of the four articles to these debates.

Article 1 responds to arguments for the conclusion that belief polarization is a rational phenomenon. It argues that, when disagreement is salient, the biased processing of evidence that results in belief polarization is incompatible with rationality, and the resulting polarized beliefs are neither reliably formed nor supported by the evidence, properly construed.

Article 2 discusses the epistemic significance of political disagreement. It shows that motivated reasoning about politically salient propositions implies that a political opposite’s familiarity with relevant evidence and their intellectual virtues are inversely correlated with their perceived probability of being right, conditional on disagreement. This presents us with a puzzle in determining how significant such disagreements are, one that cannot be escaped by denying that political disagreements in general are epistemically significant.

Article 3 discusses the impact of the beneficial effects of collective deliberation in groups with internal disagreement for the epistemic significance of discovered disagreement. It argues that these benefits can provide one with epistemic reason to maintain confidence in the face of discovered disagreement when doing so promotes epistemically fruitful deliberation.

Article 4 discusses the impact of motivated reasoning in defense of our political or cultural values for the legitimacy of democratic decision-making. It addresses the extent to which democratic authorities should be responsive to mistaken factual beliefs in the public when these beliefs are the result of motivated reasoning in defense of controversial doctrines, and whether factual beliefs, even when supported by our best science, are excluded from public reason if they are entangled in a cultural dispute.

 

 

Afhandlingen udforsker implikationerne af motiveret ræsonnering, tendensen til at ræsonnering fortolker evidens på måder, der støtter en ønsket konklusion, for normative diskussioner i uenighedens erkendelsesteori og politisk filosofi. Introduktionen giver en kort oversigt over psykologien om motiveret ræsonnering og dens konsekvenser. En af disse er polarisering af overbevisninger: Personer, der er uenige, bliver hver især mere overbeviste, efter de observerer den samme evidens. En anden konsekvens er, at deliberation i grupper med intern uenighed er en effektiv metode til epistemisk forbedring. Introduktionen giver tillige en kort oversigt over uenighedens erkendelsesteori og uenighedens rolle for politisk legitimitet, og påpeger artiklernes bidrag til disse diskussioner.

Artikel 1 svarer på argumenter for den konklusion, at polarisering af overbevisninger er et rationelt fænomen. Der argumenteres for, at forudindtaget behandling af evidens ikke er rationel, når uenighed er fremtrædende, og for at polariserede overbevisninger hverken er dannet på pålidelig vis eller er støttet af evidens.

Artikel 2 diskuterer politisk uenigheds epistemiske betydning. Den viser, at motiveret ræsonnering betyder, at der er en invers korrelation imellem ens opfattelse af en person fra den anden politiske fløjs familiaritet med evidens og deres kognitive evner på den ene side, og deres sandsynlighed for at have ret, hvis man er uenig med dem, på den anden side. Dette generer et problem omkring, hvordan vi skal bestemme sådanne uenigheders epistemiske betydning, som
ikke kan undgås ved at benægte, at politisk uenighed har nogen signifikans.

Artikel 3 diskuterer hvilke implikationer de positive effekter af diskussion i grupper med intern uenighed har for uenigheds epistemiske betydning. Der argumenteres for, at disse positive effekter kan generere en epistemisk grund til at holde fast i ens overbevisning, når man opdager uenighed, hvis dette fordrer epistemisk frugtbar diskussion.

Artikel 4 diskuterer, hvilken betydning ræsonnering motiveret af et forsvar for vores politiske og kulturelle værdier har for demokratiske beslutningsprocessers politiske legitimitet. Den adresserer i hvor vidt omfang demokratisk valgte autoriteter bør være lydhøre over for fejltagne faktuelle formodninger, når disse faktuelle formodninger er et resultat af motiveret ræsonnering i forsvar for kontroversielle kulturelle værdier. Den diskuterer også, hvorvidt faktuelle formodninger, der reflekterer ekspertkonsensus og vores bedste videnskab, bør ekskluderes fra den offentlige fornuft, når de er viklet ind i kampe om kontroversielle kulturelle værdier.

 

Assessment Committee

  • Associate Professor Thor Grünbaum, chair (University of Copenhagen)
  • Assistant Professor Scott F. Aikin (Vanderbilt University)
  • Professor Berit Brogaard (University of Miami)

Moderator of the defence

  • Associate Professor Søren Overgaard (University of Copenhagen)

Copies of the thesis will be available for consultation at the following three places:

  • At the Information Desk of the Library of the Faculty of Humanities
  • Iin Reading Room East of the Royal Library (the Black Diamond)
  • At the Department of Media, Cognition and Communication, Karen Blixens Plads 8.