Origins of IDS: PPVT scores predicts preschoolers’ speech changes to infants

• In Event: Poster Session 01
  In Poster Session: PS 01 Topic - Social Cognition

Abstract

Preschoolers begin using aspects of infant-directed speech (IDS) when speaking to infants around age 4, but it is unclear whether they do so because they recognize infants are less competent learners or if they are simply modeling adult behavior. To test the social modeling hypothesis, Weppelman and colleagues (2003) compared preschoolers’ speech to infants and adults to determine whether preschoolers with younger siblings modified their speech more than preschoolers who are only children. Their study found no significant differences in speech patterns between children with and without younger siblings. Our study, preregistered with the OSF, replicated these findings and then extended them to test a cognitive advancement hypothesis. Does a child’s ability to modify their speech to an immature communication partner relate to cognitive advances in language (i.e. PPVT-4 scores) and perspective taking? We predicted that children with more advanced language and perspective-taking skills would show greater modifications in their speech when talking to an infant as compared to an adult.
Replicating the methodology of Weppelman and colleagues (2003), 4-year-old participants (n=26) who were only children (n=11) or had an infant sibling (n=15) first engaged in several activities (e.g., toy play, book share) with the experimenter and then repeated the activities with an infant. Audio-recordings were used to identify the first 5 utterances to each interaction partner that contained content words (e.g., nouns). Mean word duration, mean frequency (pitch), and mean amplitude measures for speech to the infant and adult were calculated using PRAAT. Next, participants completed a perspective-taking battery that consisted of 3 measures: unexpected contents task, the unexpected locations task, and directors task (Fan et al., 2015). A composite score was created to indicate the participant’s ability to take another individual’s perspective (e.g., Tompkins et al., 2017). Participants’ receptive language ability was measured with the Peabody Picture Vocabulary Test (PPVT-4).
As with Weppelman and colleagues (2003), we found no significant differences in speech patterns between children with and without younger siblings on any of the measures (ps>.2). These results expand upon the existing literature by suggesting that preschoolers’ use of IDS does not occur simply as a result of social modeling. We then investigated participants’ speech to the infant using a ‘whole sentence’ sampling measure to focus on spontaneous speech rather than words elicited during a naming event. These analyses confirmed that 4-year-olds modify their pitch when speaking to infants as compared to adults. Performance on the perspective-taking battery did not predict the degree of change to pitch in speech, ps>.05. However, there was a significant positive correlation between children’s PPVT score and difference in mean standard deviation of pitch between adult and infant speech, Rs (16)= .641, p=.004. Children who showed more variability in pitch in speech to infant as compared to adult had higher PPVT scores. These results partially supported our hypothesis that advanced cognitive skills relate to the onset of IDS usage. The findings suggest a mechanistic explanation for the gradual increase in children’s use of IDS which is currently lacking in the literature.

Authors

• Rachel R Albert, Lebanon Valley College
  Presenting Author

• Savannah Toth, Lebanon Valley College
  Non-Presenting Author