Learning mechanisms influencing infants' early socio-pragmatic abilities.

Advanced pragmatic skills are hypothesized 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 infants' pre-linguistic communicative acts. In the first wave of a larger randomized controlled trial study, when their infants were around six months old, carers were randomly assigned to either a communication intervention or an active control intervention focused on physical health. When infants turned 12 months, home videos ( = 125, 64 active control intervention, 61 communication intervention) were analysed for infant pre-linguistic acts, and caregiver responses to infant pre-linguistic communication. We also examined whether these variables varied by socio-economic circumstances. Pre-registered analyses indicated that the intervention led to increases in infant communicative acts and caregiver semantically contingent responses to infant communicative behaviours. This indicates that the experience of communicating with a responsive caregiver has a causal effect on the development of the infant's pre-linguistic pragmatic skills that are thought to provide the basis for later language, pragmatics and Theory of Mind.This article is part of the theme issue 'At the heart of human communication: new views on the complex relationship between pragmatics and Theory of Mind'.