The relationship between physiology and emotions is not one-to-one

The argument

The Cannon-Bard theory is defined here by what it refutes. Refuting the notion that emotions are based on physiology, it argues that physiological symptoms and emotional states are not necessarily linked. The view being rejected holds that a bodily change comes first and the emotion is the mind's registration of it, so that fear simply is the perception of a racing heart and the reactions that accompany it. If that were right, then specifying the physiological state would be enough to specify which emotion is being felt. The counter-example offered is ordinary and decisive. During exercise, a person may experience many of the same physiological symptoms as when they are afraid, such as an elevated heart rate, sweating, and trembling. The bodily signature is the same in both cases, and the same in detail rather than merely in outline. Yet although the physiological responses are the same, exercise and frightening events do not evoke the same emotions. Nobody mistakes a hard run for terror, and the person exercising is not undergoing some muted or unrecognised version of fear. The physiological state has been held constant while the emotional state differs, which is exactly the combination the physiological account rules out. What follows is a claim about structure rather than a denial that body and feeling are related at all. The lack of one-to-one causal relationships between emotions and physiology suggests that their connection is more complex than a simple cause and effect mechanism. Something beyond the bodily response must be doing the work of settling which emotion is felt, since identical physiological responses can accompany entirely different emotional states. That is the observation the Cannon-Bard theory is built on, and the comparison between exercise and fear is the everyday case that forces it.

Premises

Counter-arguments

Later theories argue the Cannon-Bard point — that identical arousal accompanies different emotions — does not show physiology and emotion are decoupled, only that arousal alone is not sufficient. The Schachter-Singer two-factor theory, a sibling position, accepts the shared-arousal observation but explains the different emotions by adding cognitive appraisal of context, preserving a central role for physiology. Appraisal (Lazarus) and even refined James-Lange accounts likewise incorporate the same data without abandoning bodily states. So the exercise-versus-fear example undercuts a crude one-to-one physiological theory but does not establish Cannon-Bard over these rivals, which accommodate the very evidence it cites.

Rejecting the premises

[Rejecting P2] That exercise and fear share symptoms yet differ emotionally shows arousal is not sufficient for a specific emotion — but the two-factor and appraisal theories explain this by adding cognition, without denying physiology's role. [Rejecting P3] The "no one-to-one link" observation refutes only a simplistic purely-physiological account; it does not favour Cannon-Bard over rivals that also incorporate the same evidence. [Rejecting C] The example is consistent with several theories of emotion, so it supports the general point that arousal underdetermines emotion rather than establishing the Cannon-Bard theory specifically.