Masked or not, I smile to you: Exploring full-term and preterm infants' social smiles to adults wearing a protective facemask

This database includes the raw data linked with the paper “Exploring full-term and preterm infants’ social smiles to adults wearing a protective facemask”, published on Infant Behavior and Development Journal, doi: 10.1016/j.infbeh.2024.101947. This publication explores early emergence of social smiles in preterm (PT) and full-term (FT) infants at 3 months (corrected age for prematurity) and how the use of protective facemasks by adults affects the display of social smiles.

Procedures

We enrolled 30 FT and 30 PT infants (gestational age ≤ 32 weeks). Infants' social smiles displays were assessed at 2–3-month-age (corrected) across a three-episode (masked mother; unmasked mother; masked adult female stranger) videotaped interactive task. During each episode, the adult was instructed to maintain specific facial expressions (happy-smiling, sad-frowning, neutral-unresponsive) for 15 second windows and then instructed to interact spontaneously for 45 s (of which the first 15 s were coded). Social smiles were coded in each 15 s sequence as 0, absent or 1, present at least once.

Analytical plan

A 2-block hierarchical logistic regression was used, firstly testing for differences in probability of social smiles display in the three mask conditions (masked mother – MM, masked stranger – MS, and unmasked mother – UM) (Model 1) and subsequently exploring possible additional effects of group (full term – FT, preterm – PT) and facial expression (smiling, neutral, frown, and interactive) (Model 2).

Findings in brief

FT and PT infants did not differ in the display of social smiles. In both groups, social smiles were mostly exhibited in response to happy/smiling and spontaneously interacting partners. Overall, no effect of wearing a protective facemask emerged. The use of protective facemasks did not result in a lower display of social smiles. The findings suggest that FT and PT might be equally sensitive to their adult interactive partners in terms of social smiles displays at 2 – 3-month-age.