Cognitive, Affective, & Behavioral Neuroscience

, Volume 10, Issue 2, pp 208-216

First online:

Feeling we’re biased: Autonomic arousal and reasoning conflict

  • Wim De NeysAffiliated withCNRS and University of Toulouse Email author 
  • , Elke MoyensAffiliated withUniversity of Leuven
  • , Debora VansteenwegenAffiliated withUniversity of Leuven


Human reasoning is often biased by intuitive beliefs. A key question is whether the bias results from a failure to detect that the intuitions conflict with logical considerations or from a failure to discard these tempting intuitions. The present study addressed this unresolved debate by focusing on conflict-related autonomic nervous system modulation during biased reasoning. Participants’ skin conductance responses (SCRs) were monitored while they solved classic syllogisms in which a cued intuitive response could be inconsistent or consistent with the logical correct response. Results indicated that all reasoners showed increased SCRs when solving the inconsistent conflict problems. Experiment 2 validated that this autonomic arousal boost was absent when people were not engaged in an active reasoning task. The presence of a clear autonomic conflict response during reasoning lends credence to the idea that reasoners have a “gut” feeling that signals that their intuitive response is not logically warranted. Supplemental materials for this article may be downloaded from