Actions speak louder than words: The role of adaptive contingency in language development.

다국어 초록 (Multilingual Abstract)

Sensitive and responsive parenting promotes adaptive outcomes for children. Within the domain of language development, responsiveness has been examined through the effects of temporal and semantic contingency on children's vocabularies. The term adaptive contingency can be used to characterize the process whereby dyads co-construct common ground, establishing a co-dependence of both timing and meaningfulness. This dissertation examined the role of adaptive contingency in early verb learning by examining the learning consequences when timing is manipulated but meaning is held constant (Study 1) and when meaningfulness is manipulated but timing is held constant (Study 2). In a previous study, toddlers learned novel action words when teaching was uninterrupted, but failed to do so when caregivers were interrupted while teaching by a cell phone call from the experimenter (Reed, Hirsh-Pasek, & Golinkoff, in preparation). Study 1 explored how the timing of interruptions differentially affects word learning. Experimenters blind to study hypotheses taught two-year old toddlers novel words, and learning was assessed via the Intermodal Preferential Looking Paradigm (IPLP). During the teaching period, experimenters responded to text messages, momentarily disrupting the teaching. The timing of these interruptions occurred (1) in the middle of an utterance, such that the label and demonstration of its action referent were decoupled, (2) before the "label + action referent" event occurred, or (3) after (the control condition). At test, only children in the after condition learned the novel words. Study 2 examined whether word learning would be disrupted when teaching interactions were interrupted by an event that breaks the shared focus (e.g., a cell phone call) but not when the interruption shifts the shared context (e.g., when a lighted display suddenly shines). Novel words were learned in one of three experimental conditions (light display to shift attention, cell phone call to break attention, no interruption control), and learning was again assessed via the IPLP. Only toddlers in the shift condition learned the novel words. This dissertation contributes to the growing recognition that the quality of interactions with caregivers affects children's language trajectories (e.g., rich and diverse vocabulary, Rowe, 2012; fluent and connected bouts of sustained joint attention, Hirsh-Pasek et al., in press). Utilizing ecologically valid interruptions, the two studies together illuminate how the social context can support or hinder early verb learning.