Associations between shared book reading, daily screen time and infants' vocabulary size.

In the current pre-registered study, we examined the associations between shared book reading, daily screen time, and vocabulary size in 1,442 12- and 24-month-old Norwegian infants. Our results demonstrate a positive association between shared reading and vocabulary in both age groups, and a negative association between screen time and vocabulary in 24-month-olds. Exploratory analyses revealed that the positive relationship between shared reading and expressive vocabulary in 12-month-olds was stronger in lower SES groups, suggesting that shared reading may act as a compensatory mechanism attenuating potentially impoverished learning environment and parent-infant interactions in low-SES families.