Do basic emotions have distinct autonomic signatures?

The oldest live debate in this cluster, running from 1884 to present. It is the empirically tractable core of the James–Lange controversy: not the (hard-to-test) temporal claim that bodily change precedes feeling, but the specificity corollary — that emotions like fear and anger have discriminable ANS patterns.

The two poles

• Specificity (James → Ax → Ekman/Levenson → Friedman): emotions have distinct, evolutionarily adaptive visceral signatures; apparent non-specificity is an artifact of univariate measures and weak inductions. Multivariate PCA studies are the strongest support.
• Non-specificity (Cannon → activation theory → Schachter–Singer): arousal is a single diffuse sympathetic state; emotional differentiation comes from central processing or cognitive labeling.

Where the papers land

• Friedman (2010) argues the evidence tilts toward specificity and endorses Cacioppo’s continuum reconciliation (patterned ↔ undifferentiated, somatovisceral afferents causal throughout).
• Dror (2017) complicates the non-specificity pole historically: the “undifferentiated arousal” premise entered via Schachter’s social-influence program, not from a physiological demonstration — so the debate may partly rest on a historically contingent framing (see origins-of-two-factor-theory).
• Seth (2013) arguably dissolves rather than settles it: under interoceptive-inference, “specific pattern” vs “labeled arousal” are recast as differing precision on interoceptive predictions vs prediction errors.

Status: open

Meta-analyses still conflict (Cacioppo et al. 2000: valence but not discrete-emotion differentiation; Stemmler 2004: robust fear-vs-anger specificity). The basic-emotions / natural-kinds dispute (Barrett) keeps the question alive at the conceptual level.