Noun and verb acquisition in young Wichi children: New evidence from an indigenous Amerindian community

TAVERNA, A. S.; WAXMAN, S. R.

ZURICH

Conferencia; SLE 50 ANNUAL MEETING; 2017

SOCIETAS LINGUISTICA EUROPAEA

Is the noun advantage in early language development universal to all human languages, or does it reflect specific characteristics of the particular language being acquired? Addressing this question requires careful examination of lexical acquisition in diverse languages, especially those in which it has been proposed that verbs enjoy a relatively privileged status in the input (e.g., Choi & Gopnik, 1995; de Léon, 1999; Stoll, et al., 2012; Tardif et al., 1997;Waxman, et al, 2013 for a review). Here, we provide new evidence from young children acquiring Wichi, the native language of an indigenous group living in Argentina?s Chaco Forest. In Wichi, nouns and verbs are the major grammatical forms; because adjectives are not a distinct grammatical form, verbs describe not only events and activities, but also states and properties. As a result, as in other ?verb-heavy? languages, verbs are more prominent in the input than in languages like English. Moreover, in Wichi, as in other typologically-related languages, verbs are morphologically more complex than nouns (Nercesian, 2014). How does this combination of input factors shape lexical acquisition in this understudied language? To address this, we adopt a two-pronged approach. First, we consider noun:verb ratios (number of nouns divided by total number of nouns and verbs) in young Wichi children?s lexicon using two measures: a) vocabulary inventories (completed on 19 children ranging from 12 to 48 months), and b) communicative interchanges (completed on 8 Wichi children and their mothers, recorded longitudinally in their natural settings at least twice between 14 and 48 months). Second, we identify the noun:verb ratio in adult speech in these communicative interchanges. Preliminary results offer three new insights. First, analyses of children?s vocabulary inventory show: (1) a high noun:verb ratio at different developmental points from 14 to 48 months; (2) a decrease in the magnitude of noun: verb ratio from 14 to 48 months, which is correlated with vocabulary increase (r = .611, p = .005, N = 19). Second, longitudinal analyses of 3 children?s vocabularies derived from their naturalistic communicative exchanges confirm this pattern for both, type (r = .87, p = .004, N = 8) and token (r = .6, p = .08, N = 8). Finally, preliminary analyses of adult speech to these three children reveal a low noun/verb ratio at all ages. Together, these preliminary results suggest that nouns outpace verbs in Wichi early vocabulary; that the noun:verb ratio decreases gradually from 12 to 48 months, bringing it into closer alignment with the adult ratio, in spite of the complex morphology of verbs. We interpret these results in a strongly development framework, highlighting the importance of universal features of lexical development and the shaping role of the language being acquired.