Clarifying the Structure of Current Debates on Mixed Affect: Ontologies of Emotion, Models of Valence, and the Scope of Kahneman’s ‘Vacillation Hypothesis’

Felt emotional ambivalence, bittersweet emotional experience, and other cases of apparent coexistence between affectively discordant emotions raise a much-debated empirical question: do affectively discordant feelings actually coexist (Coexistence hypothesis), or do they just seem to us to do so, due to their rapid alternation (Vacillation hypothesis)? This paper seeks to clarify what is at stake in addressing this question, without thereby endorsing any of the standard answers to it as the debate is usually framed; instead, it argues that coexistence and vacillation are best treated as distinct, context‑dependent mechanisms rather than rival global accounts of mixed affect. The analysis I propose reveals that the denial of Coexistence does not directly depend on commitment to ‘bipolar’ models of affective valence as is normally accepted, since the polar opposition of pleasure and unpleasure does not by itself exclude Coexistence. Rather, this denial stems from commitment to a particular ontology of emotions, namely, the view that occurrent emotions are partly constituted from a simple , unitary core affect state that, at any given instant, must bear either positive or negative valence. Having disentangled the Vacillation hypothesis from debates about the structure of valence, the paper further argues that recent psychology literature has misinterpreted Kahneman’s ‘vacillation hypothesis’, overgeneralizing it beyond its original theoretical context. Kahneman originally proposed Vacillation for specific cases involving commensurable evaluative comparisons (e.g., framing effects in economic decision-making), not as a general account of mixed emotional affect. The paper thus distinguishes between two mechanisms: vacillation, which applies when competing evaluations operate on a shared metric, and coexistence, which applies to cases in which emotion episodes are focused on distinct, incommensurable value-aspects of emotional situations.