Restricting a Familiar Name in Response to Learning a New One: Evidence for the Mutual Exclusivity Bias in Young Two-Year-Olds

Abstract

Children under 2 1/2 years old tend to interpret novel words in accordance with the Mutual Exclusivity Principle, but tend not to reinterpret familiar words this way. Because alternative principles have been proposed that only predict the novel word effects, and because tests of the familiar word effects may have been flawed, a new test was administered. In Experiment 1 (N = 32), 24- to 25-month-olds heard stories in which a novel noun was used for an atypical exemplar of a familiar noun. When asked to select exemplars of the familiar noun, they showed a small but reliable tendency to avoid the object from the story. In Experiment 2 (N = 16), the novel nouns in the stories were replaced by pronouns and proper names, and the children did not avoid the story object in the test of the familiar noun. Thus, the aversion to this object that was observed in Experiment 1 was not due to its greater exposure or its being referenced immediately before testing, but to toddlers' Mutual Exclusivity bias. Their bias is hypothesized to be a form of implicit probabilistic knowledge that derives from the competitive nature of category retrieval.

Grounding Development in Cognitive Processes

“…And how is this knowledge brought to bear and realized in real time when a child encounters a real speaker and a novel object? Increasing evidence suggests that the answers may be found in the operating characteristics of perceiving and remembering (Merriman & Stevenson, 1997;Roberts & Jacob, 1991;Saffran, Aslin, & Newport, 1996;Smith, Jones, & Landau, 1996;Stager & Werker, 1997). We brießy consider three lines of evidence from our own work.…”

Models of the Emergence of Language

“…However, there is reason to believe that such principles are themselves emergent properties of the cognitive system. For example, Merriman and Stevenson (1997) have argued that the tendency to avoid learning two names for the same object emerges naturally from the competition (MacWhinney, 1989) between closely-related lexical items.…”

The Nominal Passover Effect Depends on Addressee Age, Speaker Goal, and Object Similarity

“…Only two types of previous studies have addressed the mechanisms by which young children identify and learn from such exemplars: investigations of whether hearing a new label for an object reduced children's tendency to apply a familiar label to it (Diesendruck et al, 1998;Gelman et al, 1989;Merriman, 1986;Merriman & Stevenson, 1997);and Merriman et al's (1995a) demonstrations that passing over an object during name training reduced 3-year-olds' tendency to select it in a forcedchoice but not a free-choice test of name generalization. The current investigation replicated and extended the latter set of findings in several important respects.…”

“…We propose that youngsters tend to identify an object as a negative exemplar of a familiar noun if the object is encountered in a situation in which a speaker is expected to label it, but does not. This process may be part of the reason for the decline that has been observed in youngsters' willingness to accept a familiar name for something after they have heard a different name used for it (Diesendruck, Gelman, & Lebowitz, 1998;Gelman, Wilcox, & Clark, 1989;Merriman, 1986;Merriman & Stevenson, 1997; but see Taylor & Gelman, 1989). However, given children's default assumption that labels have mutually exclusive extensions (Markman, 1989;Merriman & Bowman, 1989), this decline may derive as much from occurrence of the unexpected label as from failure of the expected label to occur.…”