In addition to referential uses, pronouns can have covarying interpretations, i.e., exhibit the behavior of a bound variable. The grammatical mechanism(s) behind such readings have been subject to longstanding debates: Some authors argue for a fairly flexible but unified semantic mechanism that is not tied closely to syntactic configurations. Others distinguish a core class of bona fidebinding with tight syntactic constraints from other mechanisms that give rise to ultimately parallel effects, but do so more indirectly. Psycholinguistic work has started to uncover the processing mechanisms involved in evaluating dependencies between covarying pronouns and (candidate) antecedents. Moulton and Han (2018) leverage the processing perspective to try to shed light on the theoretical question of what grammatical mechanism is at play for a given covarying pronoun. They argue that so-called Gender Mismatch Effects only arise for cases of bona fide binding, supporting the existence of distinct grammatical mechanisms. However, Kush and Eik (2019), looking at another construction involving the relevant other covariation mechanisms, do find Gender Mismatch Effects. These authors suggest that various contextual factors can make a covarying interpretation harder to obtain, and they propose adjustments to Moulton and Han’s stimuli that they think should lead to fast Gender Mismatch Effects even when no bona fide binding is involved. A series of self-paced reading experiments replicate the results from Moulton and Han, and then extend the paradigm to variations along the lines suggested by Kush and Eik. The adjustment of contextual factors indeed results in Gender Mismatch Effects for both environments. We discuss how the processing evidence informs the theoretical issues.  
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