Understanding the Naturalistic Toddler Visual Environment of Faces, Bodies, and Emotional Expressions: How Individual Differences Relate to this Socioemotional Input

Toddlerhood is a period of rapid socioemotional development. A key group of socioemotional skills relate to extracting information from faces and bodies. Knowing the role of environmental visual input in driving this development is crucial, particularly in toddlerhood, and especially given that developmental trajectories in this domain are very diverse. The first step in understanding what toddlers could learn from the environment is characterising what information is in their view. Prior research is limited but would suggest that faces specifically are infrequent in the toddler view. This thesis focuses on the degree to which toddlers see faces, bodies and facial emotional expressions (FEE) as they navigate their naturalistic home environments, as well as factors that shape individual differences in this input. Chapters 1 and 2 focus on faces and bodies, while chapters 4 and 5 focus on FEE. To contextualise toddler input, we must understand elements of mature, adult processing and viewing of faces, bodies and FEE. So, there is some discussion of adult processing, and chapter 3 focuses on adult processing of real FEE. Not only this, but we characterise the corresponding visual input of adult caregivers with respect to faces, bodies and FEE in chapters 1 and 4. Overall, we address one question: what are the natural statistics of socioemotional stimuli in the toddler visual input? We find that, as compared to caregivers, toddlers infrequently see faces, and less often see bodies. Real-world FEE are highly ambiguous, especially threat-related FEE. Both toddlers and caregivers rarely see threat-related FEE, with most faces in view being happy or neutral. Temperament and the presence of child siblings are related to individual differences in the frequency of FEE in the toddler input but not faces or bodies. This raises fundamental questions on how toddlers may learn from scarce visual input.