Publication Type: Individual Poster
Abstract: Background and Aims: Considerable research suggests an important role for children’s joint attentional skills in their vocabulary development. Children high in joint attention have relatively large vocabularies. Infant temperament has also been frequently linked with vocabulary size. Specifically, infants high in focused attention, positive in mood, and low in perceptual sensitivity are generally found to have large vocabularies. However, little research has examined the extent that temperament might play a role in children’s joint attentional skills. The purpose of the present investigation was to explore whether individual differences in infants’ temperamental profiles would predict individual differences in their joint attentional skills.
Method: Twenty-five 11-month-olds and twenty-two 14-month-olds were tested in a gaze-following procedure. Two phases were presented, each consisting of 8 trials. On each trial, the experimenter made a head turn to look at an object on the left or right side of the room. An instance of gaze following was counted when infants turned to look in the same direction as the experimenter. The Infant Behavior Questionnaire – Revised was used to assess parental report of temperament. Most relevant to the present investigation were dimensions previously found to predict vocabulary size: duration of orienting, smiling/laughter, soothability, and perceptual sensitivity.
Key Results: Frequency of gaze following was found to decrease over time, with Phase 1 gaze following (M = 4.91) significantly higher than Phase 2 gaze following (M = 3.93), F(1, 43) = 12.61, p = .001. Importantly, frequency of gaze following interacted with the temperament dimensions: duration of orienting and perceptual sensitivity. For the 11-month-olds, infants who were high in perceptual sensitivity revealed significantly greater decreases in gaze-following frequency over time than did children who were low in perceptual sensitivity [F(1, 23) = 4.18, p = .052). At 14-months, babies low in duration of orientation showed a decline in gaze following frequency, whereas high duration of orientation babies actually increased in frequency [F(1, 20) = 5.23, p = .033].
Conclusions: These results suggest that infant temperament may play an important role in the development of infants’ joint attentional skills. Before age 1, a general sensitivity to the environment may be the best predictor of whether children are willing to engage in extended bouts of gaze following during word-learning contexts. A few months later, as they become better at focused attention, duration of orientation may play a larger role than perceptual sensitivity. In sum, joint attention may be a possible mechanism underlying the links between temperament and vocabulary development previously reported in the literature.