The Dynamics of Looking and Smiling Differ for Young Infants at Elevated Likelihood for ASD

Area of Science:

• Developmental psychology
• Neurodevelopmental disorders
• Infant social interaction

Background:

• Social smiling emerges around 2 months, serving as an early communication skill.
• Infants typically smile in response to caregivers from 2-6 months, later coordinating smiles with other cues.
• Reduced social smiling is noted in older infants with autism spectrum disorder (ASD), but early development is less studied.

Purpose of the Study:

• To investigate the components of infant social smiles (looking and smiling) in 3- and 4-month-olds.
• To compare infants with elevated likelihood (EL) for ASD versus low likelihood (LL) for ASD.
• To identify early differences in social smiling that may predict later ASD diagnosis.

Main Methods:

• Observational study of face-to-face interactions between infants and caregivers.
• Analysis of social smiling behaviors (looking to caregiver, smiling) in 3- and 4-month-old infants.
• Comparison of infants categorized as EL or LL for ASD based on familial risk.

Main Results:

• No significant differences were found in the overall duration or rate of looking and smiling between EL and LL infants.
• A nuanced difference emerged in temporal dynamics: 3-month-old EL infants exhibited prolonged looking after smiling ceased.
• These findings suggest largely typical social smiling in early infancy for EL infants.

Conclusions:

• Social smiling appears typical in early infancy for infants at elevated likelihood for ASD.
• Subtle differences in the temporal coupling of looking and smiling behaviors were observed.
• Further research is needed to explore the implications of these temporal differences for social development and potential ASD prediction.