Abstract

Mother-infant interactions are fundamental to infant socio-emotional development. Through mutually regulated exchanges in the first year of life, infants develop critical communicative and regulatory skills. Infant touch is a central channel through which infants communicate their underlying affective states, regulate their emotions, and explore their surroundings. Yet despite its importance, there is a paucity of research examining infant touch. The current dissertation was designed to investigate infants' touching behaviours during mother-infant face-to-face interactions. A series of two studies investigating infant touch in the context of infants' other communicative modalities during interactions with variations in maternal availability was conducted. Study 1 examined how touch co-occurs with distal modalities (i.e. gaze, affect), and investigated the functions of touch (i.e. communicative, regulatory, exploratory). Findings revealed that touch is organized with gaze and affect into meaningful affective displays, and that infants use touch to self-regulate and explore when mothers are emotionally unavailable. The impact of the quality of the relationship (i.e. maternal emotional availability indicators, such as sensitivity and hostility) on infants' touching behaviours was also examined. Findings demonstrated greater engagement through touch in infants with more sensitive mothers. Study 2 investigated infants' touching behaviours in an at-risk sample of depressed and non-depressed mothers exhibiting poor relationship indicators (i.e. sub-optimal emotional availability). Touch was compared during periods of emotional versus physical unavailability, revealing greater reactive types of touch during physical unavailability. Findings also highlighted the impact of maternal risk on infants' touching behaviours: infants of depressed mothers exhibited more reactive types of touch compared to infants of non-depressed mothers, and negative relationship indicators (e.g. maternal hostility, intrusiveness) predicted regulatory tactile behaviours. Taken together, the present findings contribute to current knowledge on touch during early socio-emotional development. Results underscore that infants are active participants during their social exchanges and that they vary their tactile behaviours as a function of maternal availability. The findings clarify how infants use touch (i.e. to regulate, explore) when mothers are unavailable, and imply that touch serves a communicative role during pre-verbal development. Finally, this research offers insight into the impact of maternal risk on infants' regulatory abilities and the dyadic processes of co-regulation