Prolonged COVID-19 related effects on early language development: A longitudinal study

Background: There is growing evidence that COVID-19 brought changes that immediately affected early language development. Little is known for how long these COVID-19 related changes shaped development. The current study systematically and longitudinally addressed this issue, following up children's language development throughout the first 2.5 years.

Method: The present study follows up on the sample from Frota et al. (2022), which demonstrated that 7-9-month-old infants born and raised during the pandemic do not segment words unlike pre-pandemic peers. Four studies were conducted: (1) word segmentation task at 12 months of age (N_pandemic = 15); (2) word learning task at 20 months of age (N_pandemic = 20); (3) language and communication development up to 30 months of age, via CDI and CSBS parental reports (N_pandemic ranged 25-74); (4) overall development at 30 months of age using the Griffiths Developmental Scales (N_pandemic = 16).

Results: The pandemic sample consistently underperformed in all four studies in comparison to pre-pandemic data. There was no evidence of developed word segmentation abilities at 12 months of age, and no successful word learning at 20 months of age. Lexical development between 12 and 24 months of age was lower than in the pre-pandemic sample, while social communication did not seem to be affected. At 30 months of age, the pandemic sample showed lower scores and lower mental age on the Language and Communication Griffiths' subscale, in comparison to the pre-pandemic data.

Conclusions: Infants born and raised during the pandemic have a poorer language development, that persists at least until 30 months of age.