Greenwood, E., Esposito, G., Viswanathan, N. K.,  Labendzki, P., Marriott Haresign, I., Amadó, M. P., Ives, J., Lancaster, K., Northrop, T., Phillips, E. A. & Sam Wass (preprint). To match or not to match: Caregiver Vocal Contingency, Affective Matching, and Infant Communication and Distress Signalling. https://osf.io/preprints/psyarxiv/q9uyg_v1

Abstract: Infants develop communicative display through proto-conversations with caregivers. Infant vocalisations elicit responses, shaping dyadic arousal. Infant and caregiver therefore grow together as a communicative and regulatory unit. In typical development autonomic arousal is initially closely linked to distress vocalisations, while communicative vocal display gradually becomes more independent of arousal over time. Individual differences in developmental trajectories suggest variation in these patterns.

Using day-long home recordings from 5-18 month-old infants we examined how infant autonomic arousal relates to vocal behaviour and caregiver responsivity. We found a functional hierarchy in arousal–vocalisation coupling consistent with functional flexibility theory. Caregiver responsivity was arousal-contingent: higher rates of both 2-second and 5-second contingent responses during elevated arousal were associated with stronger coupling at medium–high arousal levels. Consistent with selective reinforcement theory, the more immediate window showed greater specificity and stronger effects than the proximal window.

Within arousal levels, caregiver divergence in intensity and affect predicted fewer high-intensity and increased low-intensity vocalisations at moderate (but not elevated) arousal. Overall, findings suggest two interacting developmental mechanisms: broad caregiver responsivity supporting symbolic language via functional flexibility, and arousal-specific responsivity supporting a distress ‘alarm’ function. Variation in arousal-contingent caregiver responses may help characterise both typical and atypical developmental trajectories.

Greenwood, E., Esposito, G., Labendzki, P., & Wass, Sam. (2026). Mobile Tracking in Emotion Research. 10.31234/. osf.io/xzuc5_v1

Abstract: Mobile tracking of humans has never been more widespread. Machine classification of human emotion expression aspires to human precision; but neither are very accurate at identifying the underlying ‘inner state’ of adults. Children’s inner state is more clearly aligned with communicative display; but only at very young ages. Multi-modal approaches measure involuntary biological processes such as heart rate or skin temperature alongside behavioural displays such as facial expression or speech intonation. The advancement of Artificial Intelligence (AI) makes it possible to look at more signals simultaneously over much larger datasets; although automatic classification loses the contextual subjectivity of human emotion expression.

Wass, S., Greenwood, E., Esposito, G., Smith, C., Necef, I., & Phillips, E. (2024). Annual Research Review:‘There, the dance is–at the still point of the turning world’–dynamic systems perspectives on coregulation and dysregulation during early development. Journal of Child Psychology and Psychiatry, 65(4), 481-507.https://acamh.onlinelibrary.wiley.com/doi/pdf/10.1111/jcpp.13960

Abstract: During development we transition from coregulation (where regulatory processes are shared between child and caregiver) to self-regulation. Most early coregulatory interactions aim to manage fluctuations in the infant’s arousal and alertness; but over time, coregulatory processes become progressively elaborated to encompass other functions such as sociocommunicative development, attention and executive control. The fundamental aim of coregulation is to help maintain an optimal ‘critical state’ between hypo- and hyperactivity. Here, we present a dynamic framework for understanding child–caregiver coregulatory interactions in the context of psychopathology. Early coregulatory processes involve both passive entrainment, through which a child’s state entrains to the caregiver’s, and active contingent responsiveness, through which the caregiver changes their behaviour in response to behaviours from the child. Similar principles, of interactive but asymmetric contingency, drive joint attention and the maintenance of epistemic states as well as arousal/alertness, emotion regulation and sociocommunicative development. We describe three ways in which active child–caregiver regulation can develop atypically, in conditions such as Autism, ADHD, anxiety and depression. The most well-known of these is insufficient contingent responsiveness, leading to reduced synchrony, which has been shown across a range of modalities in different disorders, and which is the target of most current interventions. We also present evidence that excessive contingent responsiveness and excessive synchrony can develop in some circumstances. And we show that positive feedback interactions can develop, which are contingent but mutually amplificatory child–caregiver interactions that drive the child further from their critical state. We discuss implications of these findings for future intervention research, and directions for future work.