Generics Are a Cognitive Default: Evidence From Sentence Processing

Generics Are a Cognitive Default: Evidence From Sentence Processing Meredith Meyer (mermeyer@umich.edu), Susan A. Gelman (gelman@umich.edu), and Sarah M. Stilwell (stilwell@umich.edu) Department of Psychology, 530 Church Street Ann Arbor, MI 48109-1043 USA Abstract sentence Dogs have four legs as Most dogs have four legs, sets quantified by most similarly do not equate to the referents of generics. Consider, for instance, that although Sharks attack swimmers is often judged as acceptable, Most sharks attack swimmers is not. Generics are thus not reducible to quantifiers conveying statistical prevalence (e.g., Cimpian, Gelman, & Brandone, 2010). Noting these sorts of distinctions, most semantic analyses impute qualitative differences between generic and quantified reference (Carlson, 2010; Leslie, 2008) and reject earlier quantificational analyses treating generics as if they contained implicit quantification (e.g., Clark, 1973). Generics instead are kind-referring (Carlson, 2010), and as such, they allow speakers to discuss entirely abstract concepts rather than sets of individuals. That is, kinds have no direct real-world instantiation, but rather are mental representations, and generics are the linguistic means of referring directly to these representations. We tested the hypothesis that generics (e.g., Dogs have four legs) are a cognitive default, thereby allowing faster and less effortful processing in comparison to quantified noun phrases (e.g., all dogs). Participants judged sentences containing either generics or universally-quantified noun phrases as true or false. Under time pressure, participants treated universally- quantified noun phrases as if they were generics (e.g., responding true to All dogs have four legs, despite the existence of three-legged dogs). Participants also took longer to respond to sentences with universal quantifiers vs. generics. Data thus support a generics-as-default account. Keywords: processing. generics; quantifiers; concepts; sentence Introduction Generic noun phrases, or generics (e.g., Giraffes have long necks) refer to kinds rather than specific individuals (e.g., Those giraffes have long necks). Due to their unique semantic and conceptual attributes, generics have attracted attention in fields as diverse as philosophy, linguistics, and psychology (Gelman, 2003; Leslie, 2008; Pelletier, 2010). Still, little is known about how generics are represented and accessed cognitively. In the current study, we examined one contemporary proposal that to date has received little direct empirical support, namely the idea that generics are a cognitive default (though see Leslie, 2008, for a theoretical and philosophical treatment). In broad form, the generics-as-default proposal holds that the referents of generics are early-acquired and easily accessible, and therefore that generics present few cognitive processing demands to speakers. Additionally, the proposal holds that processing quantified sets (e.g., all Xs, most Xs) requires more effort and draws on more sophisticated and later-developing mechanisms. An important assumption of the generics-as-default account is the claim that generics are fundamentally distinct from noun phrases marked by explicit quantifiers such as all or most. Note the contrast, for instance, between Dogs have four legs and All dogs have four legs. Whereas only one three-legged dog is needed to falsify the claim that four- leggedness applies to all dogs, generics allow for counterexamples; despite the occasional three-legged dog you may have encountered, the statement Dogs have four legs remains acceptable. Further, while one might recast the Support for the Generics-as-Default Position Recognizing the fundamental distinction between generics and quantified sets, the generics-as-default position further characterizes generics as referring to cognitively basic kind- based representations. The proposal draws empirical support from a number of observations. First, generics are ubiquitous; they have been found in every human language that has been studied (e.g., Gelman & Tardif, 1998; Goldin- Meadow, Gelman, & Mylander, 2005). However, there is no explicit word or morpheme in any language that unambiguously expresses genericity (e.g., Carlson, 2010; Leslie, 2008); instead, generics are typically signaled by a lack of marking, a pattern consistent with how default or stereotypical concepts are expressed in language (e.g., Levinson, 2000). Second, despite the impoverished marking of generics, they are acquired early in development. Corpus-based studies of English-speaking children, for example, suggest that children start to produce generics at about age 2½ years (Gelman et al., 1998), at about the same time they acquire relevant linguistic markings needed to express these forms and distinguish them from particular and/or quantified forms (e.g., nouns modified by determiners or quantifiers) (Gelman, 2004). As well, young children often have difficulty in comprehending quantifiers such as all and