When it is better to receive than to give: Syntactic and conceptual constraints on vocabulary growth

We ask how children solve the mapping problem for verb acquisition: how they pair concepts with their phonological realizations in their language. There is evidence that nouns but not verbs can be acquired by pairing each sound (e.g., 'elephant') with a concept inferred from the world circumstances in which that sound occurs. Verb meanings pose problems for this word-world mapping procedure, motivating a model of verb mapping mediated by attention to the syntactic structures in which verbs occur (Landau and Gleitman 1985, Gleitman 1990). We present an experiment examining the interaction between a conceptual influence (the bias to interpret observed situations as involving a casual agent) and syntactic influences, as these jointly contribute to children's conjectures about new verb meanings. Children were shown scenes ambiguous as to two interpretations (e.g., giving and getting or chasing and fleeing) and were asked to guess the meaning of novel verbs used to described the scenes, presented in varying syntactic contexts. Both conceptual and syntactic constraints influenced children's responses, but syntactic information largely overwhelmed the conceptual bias. This finding, with collatoral evidence, supports a syntax-mediated procedure for verb acquisition.