75% of babies and toddlers have spent more time watching TV or playing with a tablet during lockdown.
Those from disadvantaged backgrounds were more likely to have higher daily screen use, the experts said.
Researchers from Oxford Brookes and the universities of Oxford, Leeds, Warwick and East Anglia set out to explore the disruption caused to families’ lives during lockdown, particularly due to the closure of libraries, playgroups plus parks and other outdoor spaces.
They polled 500 parents of children under three during the spring on the amount of time spent doing enrichment activities – such as reading, playing and singing – and screen time both before and during lockdown.
Overall, 90% of families reported an increase in enriching activities during lockdown.
During lockdown, but not before, parents from more disadvantaged backgrounds were less likely to engage in enriching activities with their child, particularly activities requiring outdoor space and access to books.
Screen time increased for most children but the finding was even more true among those from disadvantaged backgrounds – those with a low income, lower levels of education or occupational status or from a deprived neighbourhood.
As a result, the authors have recommended communal outdoor spaces and libraries should be closed only as a last resort in lockdowns.
Children from disadvantaged families should be given extra support to promote their early development, the authors added.
University of Oxford researcher Alex Hendry said: “Children depend on high-quality interactions to support all aspects of their development.
“It is heartening to see that most families have been managing to find time to talk, read and play with their babies during this critical time, even amongst everything else going on.
“But from what parents are telling us, it is clear that during lockdown some babies have been missing out.”
Oxford Brookes University researcher Dr Nayeli Gonzalez-Gomez said: “While we know disadvantaged families often do not have access to the same opportunities for child development as their more well-off peers, these disadvantages were exacerbated by the UK lockdown.
“In particular, the closure of playgrounds and libraries has disproportionately impacted children from disadvantaged backgrounds.
“In the event of continued local lockdowns, it is vital that disadvantaged families are given extra support to promote children’s early development.
“Access to communal outdoor spaces and shared resources such as libraries should only be restricted as a last resort.”