The Social Attentional Foundations of Infants’ Learning from Third-Party Social Interactions

Human infants rely on social interactions to acquire culturally relevant knowledge about their environment. Aside from active participation (“first-party perspective”), infants encounter social interactions through third-party observation (“third-party perspective”). Despite the absence of own involvement, the mere observation of others’ interactions represents an essential source of social learning opportunities. The overarching aim of this dissertation was to deepen our understanding of the foundations of infants’ observational learning from third-party interactions. This was achieved by investigating (a) social attentional developments and motivational influences driving infants’ attention toward third-party interactions (Study 1 & 2), and (b) factors influencing infants’ attention and memory while observing third-party interactions (Study 3). Study 1 investigated how infants’ attentional orienting to third-party interactions develops in parallel with their active social attention behavior. In Experiment 1, 9.5- to 11-month-old infants looked longer than 7- to 8.5-month-olds at videos showing two adults engaging in a face-to-face interaction, when simultaneously presented with a non-interactive back-to-back scene showing the same people acting individually. Moreover, older infants showed higher social engagement (including joint attention) during parent-infant free play. Experiment 2 replicated this age-related increase in both measures and showed that it follows continuous trajectories from 7 to 13 months of age. These findings suggest that infants’ attentional orienting to others’ social interactions coincides with developments in their social attention behavior during own social interactions. Study 2 examined the incentive value of social interactions as a proximal driver of infants’ attentional orienting to third-party interactions. In a gaze-contingent associative learning task, two geometrical shape cues were repeatedly paired with two kinds of target videos showing either a dyadic face-to-face interaction or a non interactive back-to-back scene. We found that 13-monthold infants performed faster saccadic latencies and more predictive gaze shifts toward the cued target region during social interaction trials. This suggests that social interaction targets can serve as primary reinforcers in an associative learning task, supporting the view that infants find it intrinsically rewarding to observe others’ social interactions. Study 3 investigated infants’ object encoding in the context of observed social interactions. In Experiment 1, 9-month-old infants were presented with four types of videos showing one object and two adults. The scenarios varied regarding the eye contact between the adults (eye contact or no eye contact) and the adults’ object directed gaze (looking toward or away from the object). Infants showed increased object encoding, but only when seeing two adults looking at an object together, following mutual eye contact. We found an identical pattern of results in a matched first-party design during which 9-month-old infants were directly addressed by one single adult on screen (Experiment 2). Together, these findings suggest that the capacity to learn about novel objects by observing third-party interactions emerges in the first postnatal year, and that it may depend on similar factors as infants’ learning through direct social interactions at this age. The findings of all three studies are integrated in a general discussion. In summary, the results of this thesis suggest that, throughout the first year after birth, infants develop abilities and preferences enabling them to approach and efficiently learn from third-party social interactions.:General Introduction 1 1.1 The Infant As an Active Learner 2 1.2 Social Attentional Requirements of Infants’ Learning From Social Interactions 3 1.3 Motivational Mechanisms Affording Opportunities to Learn From Social Interactions 16 1.4 Infants’ Learning From Social Interactions 21 1.5 Research Gaps 26 1.6 Focus of This Dissertation 27 Study I 33 2.1 Introduction 34 2.2 Experiment I 38 2.3 Experiment II 45 2.4 General Discussion 50 Study II 55 3.1 Introduction 56 3.2 Methods 57 3.3 Results 63 3.4 Discussion 64 Study III 69 4.1 Introduction 70 4.2 Experiment I 74 4.3 Experiment II 81 4.4 General Discussion 86 General Discussion 91 5.1 Summary of Results 91 5.2 Research Contributions 93 5.3 Limitations and Future Directions 101 5.4 Overall Conclusion 114 References 115 Appendix A – Supplementary Materials Study I 137 Appendix B – Supplementary Materials Study II 148 Appendix C – Supplementary Materials Study III 152 Curriculum Vitae 167 Scientific Publications and Conference Contributions 169 Contributions of Authors 171 Declaration of Authorship 17