New Delhi, Sep 12 : Children whose families use screens a lot tend to have weaker vocabulary skills, and video games have the biggest negative effect on kids' brain development, according to a study on Thursday.

Scientists from Estonia surveyed the parents of more than 400 children about their screen use, their children's screen use, and their children's language skills.

The findings, published in the Frontiers in Developmental Psychology, found that parents who use screens a lot also have children who use screens a lot and that children's higher screen time is associated with poorer language skills.

'The research shows that during the first years of life, the most influential factor is everyday dyadic face-to-face parent-child verbal interaction,' said lead author Dr Tiia Tulviste of the University of Tartu, Estonia.

In the survey of 421 children aged between two and a half and four years old, the team asked parents to estimate how long each family member would spend using different screen devices daily. The parents were also asked to fill out a questionnaire evaluating their children's language ability.

The researchers sorted both children and adults into three screen use groups -- high, low, and moderate.

They found that parents who used screens a lot had children who also used screens a lot.

Analysing the language development of these children, the team found that children who used screens less scored higher for both grammar and vocabulary. No form of screen use had a positive effect on children's language skills.

Tulviste noted that reading ebooks and playing educational games may offer language learning opportunities, especially for older children.

But, using screens for video games had a notable negative effect on children's language skills, regardless of whether parents or children were gaming, the researcher said.

/IANS