Young children and adults use reasoning by exclusion rather than attraction to novelty to disambiguate novel word meanings.

Upon hearing a novel label, listeners tend to assume that it refers to a novel, rather than a familiar object. While this disambiguation or mutual exclusivity (ME) effect has been robustly shown across development, it is unclear what it involves. Do listeners use their pragmatic and lexical knowledge to exclude the familiar object and thus select the novel one? Or is the effect, at least in early childhood, simply based on an attraction to novelty and a direct mapping of the novel label to a novel object? In a preregistered online study with 2- to 3-year-olds (n = 75) and adults (n = 112), we examined (a) whether relative object novelty alone (without pragmatic or lexical information) could account for participants' disambiguation and (b) whether participants' decision processes involved reasoning by exclusion. Participants encountered either a known and an unknown object (classic ME condition) or two unknown objects, one completely novel and one preexposed (novelty condition) as potential referents of a novel label. Reasoning by exclusion was assessed by children's looking patterns and adults' explanations. In the classic ME condition, children and adults significantly chose the novel object and both used reasoning by exclusion. In contrast, in the novelty condition, children and adults chose randomly. Across conditions, a retention test revealed that adults remembered their prior selections, while children's performance was fragile. These results suggest that referent disambiguation is not based on relative object novelty alone. Instead, to resolve referential ambiguity, both young children and adults seem to make use of pragmatic and/or lexical sources of information and to engage in reasoning by exclusion strategies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The cognitive underpinnings and early development of children's selective trust.

Young children learn selectively from reliable over unreliable sources. However, the cognitive underpinnings of their selectivity (attentional biases or trait ascriptions) and its early ontogeny are unclear. Thus, across three studies (N = 139, monolingual German speakers, 67 female), selective-trust tasks were adapted to test both preschoolers (5-year-olds) and toddlers (24-month-olds), using eye-tracking and interactive measures. These data show that preschoolers' selectivity is not based on attentional biases, but on person-specific trait ascriptions. In contrast, toddlers showed no selective trust, even in the eye-tracking tasks. They succeeded, however, in eye-tracking tasks with the same word-learning demands, if no ascriptions of reliability were required. Thus, these findings suggest that preschoolers, but not toddlers, use trait-like ascriptions of reliability to guide their selective learning.

Pragmatics aid referent disambiguation and word learning in young children and adults.

How do children succeed in learning a word? Research has shown robustly that, in ambiguous labeling situations, young children assume novel labels to refer to unfamiliar rather than familiar objects. However, ongoing debates center on the underlying mechanism: Is this behavior based on lexical constraints, guided by pragmatic reasoning, or simply driven by children's attraction to novelty? Additionally, recent research has questioned whether children's disambiguation leads to long-term learning or rather indicates an attentional shift in the moment of the conversation. Thus, we conducted a pre-registered online study with 2- and 3-year-olds and adults. Participants were presented with unknown objects as potential referents for a novel word. Across conditions, we manipulated whether the only difference between both objects was their relative novelty to the participant or whether, in addition, participants were provided with pragmatic information that indicated which object the speaker referred to. We tested participants' immediate referent selection and their retention after 5 min. Results revealed that when given common ground information both age groups inferred the correct referent with high success and enhanced behavioral certainty. Without this information, object novelty alone did not guide their selection. After 5 min, adults remembered their previous selections above chance in both conditions, while children only showed reliable learning in the pragmatic condition. The pattern of results indicates how pragmatics may aid referent disambiguation and learning in both adults and young children. From early ontogeny on, children's social-cognitive understanding may guide their communicative interactions and support their language acquisition. RESEARCH HIGHLIGHTS: We tested how 2-3-year-olds and adults resolve referential ambiguity without any lexical cues. In the pragmatic context both age groups disambiguated novel word-object-mappings, while object novelty alone did not guide their referent selection. In the pragmatic context, children also showed increased certainty in disambiguation and retained new word-object-mappings over time. These findings contribute to the ongoing debate on whether children learn words on the basis of domain-specific constraints, lower-level associative mechanisms, or pragmatic inferences.