Abstract
<p>Two of the most widely used affect instruments label their subscales identically and are reported interchangeably, yet they do not measure the same thing. The Scale of Positive and Negative Experience (SPANE) marks the valence axis of the affective circumplex; the Positive and Negative Affect Schedule (PANAS) sits on the high-activation diagonals, where valence is fused with arousal. We quantify this divergence by decomposing both instruments into content-defined valence, activation, and discrete emotion factors, and testing which content predicts life satisfaction. Across two independent samples (N = 496 and N = 749), prediction ran entirely through valence: the arousal variance that distinguishes the PANAS from the SPANE added nothing to the prediction of a hedonic judgment. Because neither battery samples low-arousal states, this result is scoped to the high-arousal range the PANAS covers. The PANAS functions as a valence measure carrying additional arousal variance, and Positive Affect names a different construct in each instrument, a difference the shared label conceals.</p>