Curiosity is considered the intrinsic drive to explore the world and discover new things we want to learn about. It has also been linked to enhanced memory formation and beneficial developmental outcomes in adults. It has been conceptualised mainly from one of two perspectives: as a state triggered by features of the environment (e.g. novelty, uncertainty, surprise) or as a personality trait impacting how we perceive and approach such information. Even though curiosity is evidently a crucial developmental construct, neither perspective nor the interaction between state and trait curiosity in infancy is well understood and research is long overdue.
This thesis comprises four empirical studies offering methodological innovations in the conceptualisation and measurement of infants state and trait curiosity. Study 1 introduces a novel, gaze-contingent eye-tracking paradigm that captures infants’ dynamically evolving state curiosity through their information sampling choices. Study 2 demonstrates the development and validation of the Infant and Toddler Curiosity Questionnaire (ITCQ), which measures trait curiosity in infants aged 5 to 24 months via caregiver reports. Study 3 examines the correspondence between these manifestations of state and trait curiosity, and Study 4 validates the ITCQ’s predictive strength by applying the new measure to early language development - one of the most prevalent areas of developmental research.
The results suggest that infants dynamically structure their exploration based on their preceding engagement with the encountered information, with some of the observed variance within such active exploration explained by individual differences in trait curiosity. Furthermore, exploration tendencies as a manifestation of infants’ trait curiosity differentially predict vocabulary size one year later, demonstrating its benefits but also revealing potential risks. Overall, this set of empirical findings evidences that infants are curious learners and that the correspondence between their state and trait curiosity is already measurable and informative early in development. Importantly, this work opens up new avenues for future research and advances our understanding of infant curiosity holistically.