What can research on nonhumans tell us about human dissonance?

Abstract

Zentall's thoughtful review of the literature on cognitive dissonance in nonhumans helps to highlight the common finding that similar outcomes in humans and nonhumans can be attributed to different underlying mechanisms. I advocate a more fully comparative approach to the underlying mechanisms, avoiding the assumption of shared processes in humans and nonhumans. Jennifer Vonk is an associate professor at Oakland University in Rochester, Michigan. She is the director of the Laboratory of Cognitive Origins, and has studied a wide range of cognitive processes and behaviors in a wide range of species, resulting in 50 peer-reviewed journal publications and more than 30 edited chapters and commentaries. http://www.jennifervonk.com/ Zentall (2016) has written an excellent review of the debate regarding apparent cognitive dissonance in nonhumans. These effects-e.g., altered preferences for items or rewards after differential choice or effort-have been attributed to the need to resolve inconsistencies between one's beliefs and behaviors or between one's beliefs. Research on nonhuman animals suggests that such effects may arise from processes that are not under conscious control. For example, Zentall attributes similar preferences-for rewards or cues of reward that follow greater effort, or otherwise more aversive events-to what he terms "within-trial contrast effects." Zentall's target article reveals a very clever experimental approach to uncovering the mechanisms responsible for apparent dissonance-based decisions and preferences in nonhumans. In the studies he reviews, researchers have carefully controlled for time between actions and reward, arousal at the time of reward and so on, allowing them greater confidence in attributing preferences to the contrast between the aversive event and the subsequent reward. I have no issues with the experiments as conducted, or with the logic of the interpretation of their results. However, the discussion does lead me to reflect on the following observations. First, it strikes me that there is an unexplored potential link between cognitive dissonance, as defined in humans, and the capacity for metacognition. Nonhuman animals presumably do not experience the full suite of metacognitive abilities (Smith, Coutinho, Boomer,