A longitudinal investigation of the still-face effect at 6 months and joint attention at 12 months

An understanding of intentionality is thought to underlie developing joint attention. Similarly, early social-communicative behaviours have been argued to reflect an appreciation of adult intentionality. This study explored the relation between social-communicative behaviours during the still-face effect at 6 months and joint attention at 12 months in a longitudinal sample of 42 infants. Three types of joint attention were investigated: coordinated joint attention (infant alternates looks between an adult and objects), initiating joint attention (infant uses communicative gestures to engage or direct adult attention) and attention following (infant follows an adult's line of gaze and pointing towards an object). The still-face effect was correlated with later attention following, but not coordinated or initiating joint attention. Initiating joint attention was correlated with coordinated joint attention. We propose that the former association reflects a lower-level detection of adult intentionality rather than a higher-level interpretation of an agent's intentions towards outside entities. The findings support two bodies of research - one advocating for a distinction between types of joint attentional ability and a second proposing that infants can detect intentional actions without understanding or attributing mental states to objects.