We further fitted reduced models including only the interaction between lockdown.stage and screen.time given that this interaction was near-significant in the full model for expressive vocabulary, χ2 = 3.52, df = 1, p = 0.060 (see Table 12 in Supplementary Information).
While the results with regards to the significant interaction between lockdown.stage*screen.time should be treated with caution due to the marginally non-significant interaction in the full model, they suggest that those children who had smaller increases in screen time during lockdown relative to prior to lockdown were reported to have larger increases in expressive vocabulary during lockdown (see Fig. 5 ).