Proceedings of the Annual Meeting of the Cognitive Science Society

Stress is typically conceptualized as varying along a single intensity dimension, yet individuals with identical "high stress" labels often exhibit divergent responses. This work challenges this unidimensional model through FenoStressNet, a multimodal framework integrating facial thermal imaging, physiological monitoring, psychological assessment, and explainable AI. Analyzing 120 participants across controlled stress-induction tasks (19,200 thermal images), this study identifies four reproducible stress phenotypes that cross-cut traditional intensity categories: Cognitive-Dominant (elevated cognitive appraisal, moderate physiology), Physiological-Reactive (rapid autonomic arousal), Integrated-Responder (synchronized multimodal activation), and Discordant-Denier (high physiological response with low subjective awareness). These phenotypes exhibit distinct facial thermal patterns and differential weighting of cognitive, affective, and physiological components. These findings suggest a paradigm shift from intensity-based to phenotype-informed stress assessment, with significant implications for personalized interventions and cognitive theories of emotion.