Neural bases of motivated reasoning: An fMRI study of emotional constraints on partisan political judgment

in the 2004 U.S. Presidential Election 

Adelle Dinkelman and Kevin Lee

Abstract• Cold reasoning vs. Emotion-biased motivated reasoning

• Tested with neuroimaging

• 2004 US Presidential Election

• 30 committee partisans (15 Democrat and 15 Republicans)

Introduction• Bounded rationality models (Simon, 1990)• Motivated Reasoning (Westen & Blagov)• Defense of aversive feelings (Freud, 1933)• Evidence that political decisions can be influenced by emotions (Bill

Clinton impeachment, 2000 Presidential Election, torture in Iraq) (Westen et al., 2005)• Hypothesis• Reasoning threatening information about supporting party will

activate implicit emotion regulation regions in the brain (VMPFC, anterior cingulate cortex)

Method• Participants• 15 Democrats and 15 Republican

• Right-handed men, 22-55 years, who were committed to their party

• Political attitudes questionnaire by National Election Studies

• Only the strong Democrat or Republicans were recruited (30+ in points for their party in the NES Questionnaire)

Methods Cont.• Measures and Procedures• 3 targets (Democrat, Republican,

Neutral)

• 6 sets of statements for each party

• 7 slides per set of statements

Methods Cont.• Planned Comparisons

1. Same-party vs. neutral during contradiction phase to isolate parts of the brain that controlled implicit emotion regulation

2. Contradiction vs. exculpatory statements in same-party to see where the brain is engaged in emotion-biased motivated reasoning

3. Interaction

Results• Democrats and Republicans drew different conclusions about contradictions by

preferred candidates• Bush:• Democrat M = 3.79• Republican M = 2.16

• Kerry:• Democrat M = 2.60• Republican M = 3.55

• Shows powerful effects of motivated reasoning

• Reasoned similarly about contradictions of neutral candidates

• Areas activated when threatening information to preferred candidate was presented vs. neutral• These areas have been shown to relate to emotional reasoning,

moral evaluations, etc

• Areas activated when threatening information compared to nonthreatening information (exculpatory phase)• Areas related to emotional processing and negative affect

• Areas more active when processing threatening versus exculpatory information related to their candidate compared to a neutral candidate (interaction)• Consistent with predictions that same-party contradictions would

activate negative processing affect regions

• After participants had considered the contradiction, and then were asked to consider it again after receiving the exculpatory information, regions related to negative affect processing no longer active• Regions for reward or reinforcement active (possible relief after

resolving emotional conflict)

Discussion• Consistent with prior studies in partisan biases and motivated

reasoning

• Implicit emotion regulation areas in the brain are different from “cold” decision making and explicit emotion regulation areas• Not associated with activation of DLPFC

• Supports theories of network of motivated reasoning

Limitations• Study of the whole brain instead of specific areas

• Narrow demographics• All men• All right-handed• Ages 22-55• No mention of race (?)• Only extreme democrats or republicans

• Can’t be certain when motivational reasoning started