Determinants of responsiveness to infant vocal expression of emotional state

Abstract

This study examines whether voiced sounds from the interactional vocal repertoire of 2-month-old infants transmit information on the infants' behavioral-emotional state and to what degree the ability to decade state-related information depends on the recipient's age, gender, parental status, and experience. The emotional state in 50 infant vocalizations produced during states of comfort, joyful excitement, discomfort, and crying and presented in a random sequence was estimated on an “Infant State Barometer” by mothers and fathers of 2-month-olds, multiparous and primiparous mothers, speech therapists, and children. Infant state estimates were analyzed as a function of sound category and subject group. Infant vocalizations were found to provide both discrete and graded information along a comfort/discomfort dimension. The data suggest that the decoding abilities of recipients are determined by the interaction of a universal predisposition with experience and age, but not by gender or parental status. Experience and age have no impact in relation to sounds of severe discomfort but are crucial in relation to age-specific expressions of joy. The functional significance of infant vocal signaling beyond the cry in close-range parent-infant interactions is discussed in relation to the parents' intuitive didactic care for the development of prelinguistic communication in infants.