Self-prioritization effects (SPE; Sui et al., 2012) and related we-prioritization effects (WPE; Constable et al., 2019) are typically interpreted as reflecting genuinely prioritized processing of self-related stimuli. We propose that these effects can, at least in part, be explained by the Polarity Correspondence Principle (PCP; Proctor & Cho, 2006). According to the PCP, binary classification tasks involve asymmetric processing of stimulus and response alternatives: one category serves as the reference (+ polar), while the opposite category is evaluated relative to it (– polar). Responses are faster when stimulus and response poles correspond. We assume that in matching tasks, self- and other-related stimuli as well as response alternatives are processed asymmetrically, with self-related stimuli and matching responses as reference categories (+). The SPE thus arises because self-related matching trials exhibit polarity correspondence, whereas other-related matching trials do not. To test this, participants learned associations between geometric shapes and self- or other-relevant labels. In a between-subject design, they affirmed either “mono-combinations” (label and shape refer to the same person) or “duo-combinations” (label and shape refer to different persons). According to the PCP, matching self-related trials are “+++” in the mono condition but “++–” in the duo condition. As predicted, a clear SPE emerged in the mono condition but was significantly reduced in the duo condition. Applying the same logic to the WPE yielded similar results. These findings suggest that a substantial part of self- and we-prioritization effects can be accounted for by the Polarity Correspondence Principle.