Individual Differences in Early Imitation are Associated with Temperament

1. 4x 4 seconds Tongue protrusion 4x 4 seconds /a/ sound 20 seconds pause 25 seconds pause 4 x 4 seconds Mouth opening 4 x 4 seconds /m/ sound 20 second pause 25 second pause Individual Differences in Early Imitation are Associated with Temperament Elma Hilbrink, Elena Sakkalou, Kate Ellis-Davies, Nia Fowler, Merideth Gattis School of Psychology, Cardiff University • Background • Radically different explanations have been proposed for early imitation. • Nativistaccounts suggest infants are born with an innate system for imitation that connects representations of self and other.1 • Arousalaccounts suggest that what looks like imitation is simply exploration elicited by interesting and therefore arousing stimuli2. • Associativelearning accounts suggest imitation develops slowly, via learned associations between perceived and executed actions.3 • All theories focus on group performance, despite evidence that variability in imitation may be associated with meaningful aspects of development. • The current study is part of the First Steps study which follows 38 infants from birth till 18 months. We compared the predictions of current theories against individual differences in imitation and temperament observed longitudinally at 2, 3 and 4 months. • Predictions: • Nativist: Early imitation at the group level, does not allow for individual differences • Arousal: No early imitation, the imitative behaviours observed can be explained by arousal • Associativelearning: No early imitation, development of imitation is a slow learned process .. Results Imitation at group level At the group level no significant differences were found for condition  No imitation at the group level Individual differences Behavioural arousal and auditory-oral Matching: Temperament and Auditory-oral matching: Temperament and facial gestures (TP/MO): • Method • Imitation measures • Auditory-oral matching4. tested at months 2, 3 and 4. • Tongue protrusion and mouth opening1 tested at 2 months. • Individual differences • Definition of imitators and non-imitators (Ferrari et al 2009)6. • Imitators (N=23): imitation stable / increased across observations. • Non imitators (N=14): imitation unstable / decreased / not observed. • For TP/MO: infants who matched at least 1 of the gestures were classed as imitators (N=28) • Behavioural Arousal: Behaviour and state at 4 months coded for ‘alert gross motor movement’ and ‘alert no gross motor movement’ (adapted from Thelen et al, 2002).5 • Temperament: Infant Behaviour Questionnaire-Revised. Scales: Vocal reactivity, Activity and High intensity pleasure. Repeat 4 times Repeat 4 times n.s. n.s. Repeat 3 times Repeat 3 times * n.s. * n.s. n.s. n.s. • Summary of results • According to the nativistaccount we should not have found significant individual differences. •  At the group level, imitation was not observed, but at the individual level, it was: for 62% of infants, imitation remained stable or increased from 2 to 4 months. • According to the arousal theory observed imitative behaviours should correlate with behavioural arousal. •  Imitation at the individual level is not explained by arousal: imitators and non-imitators did not differ on behavioural arousal,nor on the activity level scale of the IBQ-R. • According to associativelearning imitation does not develop until the second year because it is a slow process. • 62% of infants demonstrated stable or increased imitation from 2 to 4 months • According to dynamic systems accounts of development, early differences between infants can lead to differences in learning. •  Significant differences were found on the vocal reactivity and high intensity pleasure scale between imitators and non-imitators in the auditory-oral matching task. This difference suggests infant contribution to social interaction plays an important role in learning to imitate •  Failure to find significant differences between imitators and non-imitators on the facial gesture task suggest modality specific learning. • Conclusions • We propose a new model of the development of early imitation, based on Marler’s7 work on bird song. In our view, individual differences in stimulus-seeking and modality-preferences bias infants to attend to certain types of stimuli. The interplay between the infant’s preferences and its social environment further biases learning by influencing future inputs. This biased learning process is quick, evidenced by our observation that infants differ in imitative capacity from very early in life.  * HilbrinkEE@cardiff.ac.uk