A new preprint study presents the alarming finding that children born during the pandemic in the US show reduced verbal, motor, and overall cognitive performance compared to children born pre-pandemic. In the decade preceding the pandemic, the mean IQ score on standardized tests for children aged between three months and three years of age hovered around 100, but for children enrolled in this study born during the pandemic that number dropped to 78.
The study’s authors from Rhode Island Hospital and Brown University used a large ongoing longitudinal study of child neurodevelopment, known as the RESONANCE study at Brown University to examine general childhood cognitive scores in 2020 and 2021 against the preceding decade (2011-2019). Analyses of cognitive development were assessed using the Mullen Scales of Early Learning, a population normed and clinically administered tool that assesses function across the five primary domains of fine and gross motor control, visual reception, and expressive and respective language via direct observation and performance.
The study included 672 healthy children between 3 months to 3 years of age from the state of Rhode Island in the United States. The study population was controlled for age, gender, demographic, and socioeconomic indicators.
The first 1,000 days of a child’s life are an important and sensitive period of child development. Environmental factors, including maternal mental and physical health, nutrition, stimulation, and supportive caregiving can affect the developing fetal and infant brain. The researchers found that even in the absence of direct infection, the environmental changes associated with the pandemic are significantly and negatively affecting infant and child development. Males and children in lower socioeconomic families were the populations most affected. Given this data comes from a relatively affluent part of the US, I am deeply concerned about the neurodevelopment of already marginalized low socioeconomic populations both domestically and internationally.
The study’s authors write that “infants are inherently competent in their ability to initiate relationships, explore, seek meaning, and learn; but are vulnerable and depend entirely on caregivers for their survival, emotional security, modeling of behaviors, and the nature and rules of the physical and socio-cultural world that they inhabit.”
With the isolation, lack of family or caregiver support, and limited stimulation and socialization enforced by Covid-19 public health guidelines, many infants have been deprived of normal developmental experiences. Due to the financial stressors of the pandemic and limited childcare options, home environments have also become more stressful and unstable. Forced to simultaneously juggle work and childcare, parents may not be able to devote significant time to creating enriching environments for infants. Lead study author Sean Deoni, associate professor of pediatrics research at Brown University, told the Guardian “Parents are stressed and frazzled … that interaction the child would normally get has decreased substantially.”
With such dramatic results in a small sample size, we must consider the variables that may have influenced or biased the result. The study’s authors acknowledge that they did not investigate the impact of mask-wearing by the study staff during child visits and assessments. The inability of infants to see full facial expressions may have eliminated non-verbal cues, muffled instructions, or otherwise altered the understanding of the test questions and instructions. Yet the children born before the pandemic and followed through the initial stages, do not show a reduction in skills or performance, despite also completing the assessments with mask-wearing staff.
Whether these lower cognitive scores will have a long-term impact is presently unclear. But given the magnitude of the problem uncovered in this study, a more substantive body of global research on this issue is urgently needed to develop evidence-based guidelines of care for expectant mothers, design effective strategies for follow-up care and support of affected infants. Such research could also provide informed guidance for school and daycare reopening and the provision of in-person and virtual learning.