Adults design utterances to match listeners' informational needs by making both “generic” adjustments (e.g., mentioning atypical more often than typical information) and “particular” adjustments tailored to their specific interlocutor (e.g., including things that their addressee cannot see). For children, however, relevant evidence is mixed. Three experiments investigated how generic and particular factors affect children's production. In Experiment 1, 4‐ to 5‐year‐old children and adults described typical and atypical instrument events to a silent listener who could either see or not see (...) the events. In later extensions, participants described the same events to either a silent (Experiment 2) or an interactive (Experiment 3) addressee with a specific goal. Both adults and 4‐ to 5‐year‐olds performed generic adjustments but, unlike adults, children made listener‐particular adjustments inconsistently. These and prior findings can be explained by assuming that particular adjustments can be costlier for children to implement compared to generic adjustments. (shrink)

The underlying structures that are common to the world's languages bear an intriguing connection with early emerging forms of “core knowledge”, which are frequently studied by infant researchers. In particular, grammatical systems often incorporate distinctions that reflect those made in core knowledge. Here, I argue that this connection occurs because non-verbal core knowledge systematically biases processes of language evolution. This account potentially explains a wide range of cross-linguistic grammatical phenomena that currently lack an adequate explanation. Second, I suggest that developmental (...) researchers and cognitive scientists interested in knowledge representation can exploit this connection to language by using observations about cross-linguistic grammatical tendencies to inspire hypotheses about core knowledge. (shrink)

All languages, both spoken and signed, make a formal distinction between two types of terms in a proposition – terms that identify what is to be talked about (nominals) and terms that say something about this topic (predicates). Here we explore conditions that could lead to this property by charting its development in a newly emerging language – Nicaraguan Sign Language (NSL). We examine how handshape is used in nominals vs. predicates in three Nicaraguan groups: (1) homesigners who are not (...) part of the Deaf com- munity and use their own gestures, called homesigns, to communicate; (2) NSL cohort 1 signers who fashioned the first stage of NSL; (3) NSL cohort 2 signers who learned NSL from cohort 1. We compare these three groups to a fourth: (4) native signers of American Sign Language (ASL), an established sign language. We focus on handshape in predicates that are part of a productive classifier system in ASL; handshape in these predicates varies sys- tematically across agent vs. no-agent contexts, unlike handshape in the nominals we study, which does not vary across these contexts. We found that all four groups, including home- signers, used handshape differently in nominals vs. predicates – they displayed variability in handshape form across agent vs. no-agent contexts in predicates, but not in nominals. Variability thus differed in predicates and nominals: (1) In predicates, the variability across grammatical contexts (agent vs. no-agent) was systematic in all four groups, suggesting that handshape functioned as a productive morphological marker on predicate signs, even in homesign. This grammatical use of handshape can thus appear in the earliest stages of an emerging language. (2) In nominals, there was no variability across grammatical con- texts (agent vs. no-agent), but there was variability within- and across-individuals in the handshape used in the nominal for a particular object. This variability was striking in homesigners (an individual homesigner did not necessarily use the same handshape in every nominal he produced for a particular object), but decreased in the first cohort of NSL and remained relatively constant in the second cohort. Stability in the lexical use of handshape in nominals thus does not seem to emerge unless there is pressure from a peer linguistic community. Taken together, our findings argue that a community of users is essential to arrive at a stable nominal lexicon, but not to establish a productive morpholog- ical marker in predicates. Examining the steps a manual communication system takes as it moves toward becoming a fully-fledged language offers a unique window onto factors that have made human language what it is. (shrink)

This article has two goals. First, it synthesizes and critically assesses current scientific knowledge about the cognitive bases of human tool use. Second, it shows how the cognitive traits reviewed help to explain why technological accumulation evolved so markedly in humans, and so modestly in apes.

The underlying structures that are common to the world's languages bear an intriguing connection with early emerging forms of “core knowledge” (Spelke & Kinzler, 2007), which are frequently studied by infant researchers. In particular, grammatical systems often incorporate distinctions (e.g., the mass/count distinction) that reflect those made in core knowledge (e.g., the non-verbal distinction between an object and a substance). Here, I argue that this connection occurs because non-verbal core knowledge systematically biases processes of language evolution. This account potentially explains (...) a wide range of cross-linguistic grammatical phenomena that currently lack an adequate explanation. Second, I suggest that developmental researchers and cognitive scientists interested in (non-verbal) knowledge representation can exploit this connection to language by using observations about cross-linguistic grammatical tendencies to inspire hypotheses about core knowledge. (shrink)

We investigate a possible universal constraint on spatial meaning. It has been proposed that people attend preferentially to the endpoints of spatial motion events, and that languages may therefore make finer semantic distinctions at event endpoints than at event beginnings. We test this proposal. In Experiment 1, we show that people discriminate the endpoints of spatial motion events more readily than they do event beginnings—suggesting a non-linguistic attentional bias toward endpoints. In Experiment 2, speakers of Arabic, Chinese, and English each (...) described a set of spatial events displayed in video clips. Although the spatial systems of these languages differ, speakers of all three languages made finer semantic distinctions at event endpoints, compared to event beginnings. These findings are consistent with the proposal that event endpoints are privileged over event beginnings, in both language and perception. (shrink)

This paper describes a comprehensive survey of English verbs that semantically allow or require an Instrument role. It sheds light on the nature of Instrument roles and instrumentality by examining the distribution in semantic space of those verbs. We show first that verbs that semantically require instruments are typically semantically more complex than predicted by current theories of the structural complexity of verb meanings. We also show that verbs that require or allow instruments constrain the end states of situations they (...) describe more than they constrain the agent's initial activity. Our survey further suggests that the causal role played by the instrument is more varied than suggested by previous studies and requires the introduction of a new subtype of causal relation, which we dub helping. Finally, our survey demonstrates that verbs that semantically require an instrument cluster together more closely in semantic space and constrain the instrument's role and properties more than verbs that merely allow the presence of an instrument. (shrink)