Person:

Snedeker, Jesse

To use natural language, speakers must map the participants in events or states in the world onto grammatical roles. There remains considerable disagreement about the nature of these so-called linking rules (Levin & Rappaport Hovav, 2005). In order to probe the nature of linking rules, we investigate verbs of psychological state, which demonstrate complex linking patterns both within and between languages. We find that the typical duration of the psychological state guides the application of linking rules to novel verbs in both English and Japanese, consistent with a universal constraint. Nonetheless, there are marked differences in the baseline preferences for the individual linking rules across the two languages. We discuss these findings both in terms of theories of exceptionless linking rules and accounts on which linking rules are governed by probabilistic biases as well as cross-linguistic variation.

In acquiring language, children must learn to appropriately place the different participants of an event (e.g., causal agent, affected entity) into the correct syntactic positions (e.g., subject, object) so that listeners will know who did what to whom. While many of these mappings can be characterized by broad generalizations, both within and across languages (e.g., semantic agents tend to be mapped onto syntactic subjects), not all verbs fit neatly into these generalizations. One particularly striking example is verbs of psychological state: The experiencer of the state can appear as either the subject (Agnes fears/hates/loves Bartholomew) or the direct object (Agnes frightens/angers/delights Bartholomew). The present studies explore whether this apparent variability in subject/object mapping may actually result from differences in these verbs’ underlying meanings. Specifically, we suggest that verbs like fear describe a habitual attitude towards some entity whereas verbs like frighten describe an externally caused emotional episode. We find that this distinction systematically characterizes verbs in English, Mandarin, and Korean. This pattern is generalized to novel verbs by adults in English, Japanese, and Russian, and even by English-speaking children who are just beginning to acquire psych verbs. This results support a broad role for systematic mappings between semantics and syntax in language acquisition.

While the referent of a nonreflexive pronoun clearly depends on context, the nature of these contextual restrictions is controversial. The present study seeks to characterise one representation that guides pronoun resolution. Our focus is an effect known as “implicit causality”. In causal dependant clauses, the preferred referent of a pronoun varies systematically with the verb in the main clause (contrast Sally frightened Mary because she … with Sally feared Mary because she…). A number of researchers have tried to explain and predict such biases with reference to semantic classes of verbs. However, such studies have focused on a small number of specially selected verbs. In Experiment 1, we find that existing taxonomies perform near chance at predicting pronoun-resolution bias on a large set of representative verbs. However, a more fine-grained taxonomy recently proposed in the linguistics literature does significantly better. In Experiment 2, we tested all 264 verbs in two of the narrowly defined verb classes from this new taxonomy, finding that pronoun-resolution biases were categorically different. These findings suggest that the semantic structure of verbs tightly constrains the interpretation of pronouns in causal sentences, raising challenges for theories which posit that implicit causality biases reflect world knowledge or arbitrary lexical features.

Famously, dog bites man is trivial whereas man bites dog is news. This illustrates not just a fact about the world but about language: to know who did what to whom, we must correctly identify the mapping between semantic role and syntactic position. These mappings are typically predictable, and previous work demonstrates that young children are sensitive to these patterns and so could use them in acquisition. However, there is only limited and mixed evidence that children do use this information to guide acquisition outside of the laboratory. We find that children understand emotion verbs which follow the canonical CAUSE–VERB–PATIENT pattern (Mary frightened/delighted John) earlier than those which do not (Mary feared/liked John), despite the latter's higher frequency, suggesting children's generalization of the mapping between causativity and transitivity is broad and active in acquisition.

In many contexts, pronouns are interpreted as referring to the character mentioned first in the previous sentence, an effect called the ‘first-mention bias’. While adults can rapidly use the first-mention bias to guide pronoun interpretation, it is unclear when this bias emerges during development. Curiously, experiments with children between two and three years old show successful use of order of mention, while experiments with older children (four to five years old) do not. While this could suggest U-shaped development, it could also reflect differences in the methodologies employed. We show that children can indeed use first-mention information, but do so too slowly to have been detected in previous work reporting null results. Comparison across the present and previously published studies suggests that the speed at which children deploy first-mention information increases greatly during the preschool years.

Language comprehension involves not only constructing the literal meaning of a sentence but also going beyond the literal meaning to infer what was meant but not said. One widely studied test case is scalar implicature: The inference that, e.g., Sally ate some of the cookies implies she did not eat all of them. Research is mixed on whether this is due to a rote, grammaticalised procedure or instead a complex, contextualised inference. We find that in sentences like If Sally ate some of the cookies, then the rest are on the counter, that the rest triggers a late, sustained positivity relative to Sally ate some of the cookies, and the rest are on the counter. This is consistent with behavioural results and linguistic theory suggesting that the former sentence does not trigger a scalar implicature. This motivates a view on which scalar implicature is contextualised but dependent on grammatical structure.