Learning mechanisms influencing infants’ early socio-pragmatic abilities

Advanced pragmatic and Theory of Mind skills are hypothesised to depend on early experience of interaction. However, we do not yet fully understand the causal pathways involved. In the current study, we explored one potential early learning mechanism by assessing whether increasing caregiver responsiveness to infant communication in turn promotes infant’s prelinguistic communicative acts. In the first wave of a larger RCT study, when their infants were around 6 months, caregivers were randomly assigned to either a communication intervention or an active control intervention focused on physical health. When infants turned 12 months, home videos (N = 125, 64 active control intervention, 61 communication intervention) were analysed for overall caregiver responsive linguistic interaction, infant pre-linguistic acts, and caregiver responses to these acts. We also examined whether these variables varied by socioeconomic circumstances. Pre-registered analyses indicated the intervention led to increases in overall caregiver linguistic responsiveness, infant communicative behaviours, and caregiver semantically contingent responses to infant communicative acts. This indicates that experience of communicating with a responsive caregiver has a causal effect on the development of the infant pre-linguistic pragmatic skills that are thought to provide the basis for later language, pragmatics and Theory of Mind.