Children spend so much time in front of the television and computer games, and so little time with adults that one child in six has difficulty learning to talk, according to an expert appointed by the government to improve young people's communication skills.

Results of a YouGov survey published today by Jean Gross, the new "communication champion" for children, found that twice as many boys struggle as girls, and almost one in four of all children who have problems talking and understanding speech get no help. Gross, who commissioned the survey, warned that anecdotal evidence showed that left unaided children risked developing mental health problems or getting into trouble with the law later in life.

"This really matters," Gross said. "Our ability to communicate is fundamental and underpins everything else."

Nearly a quarter of boys have some difficulties, and 5% experience significant trouble, the YouGov survey of 1,000 parents in England revealed. For girls, the survey's figures are 13% and 2%.

While most children spoke their first word between 10 and 11 months, more girls than boys – 34% against 27% – did so before they reached nine months. Some 4% of children had not said their first word by the age of three. Dada and Daddy were the most common first words, beating Mama and Mummy by a considerable distance. After references to parents came "cat", "car", "no" and "dog".

Gross, an educational psychologist, said that while a proportion of children had always had speech problems there was anecdotal evidence of an increase in difficulties caused by social factors such as the amount of time they spent "exposed to screens of all kinds" and lack of time with their parents for face-to-face conversation.

"It's money – mortgages," she said. "People would feel able to share childcare or spend more time at home with their children if they didn't have to pay such astronomically high mortgages.

"Financial pressures through the housing market have made a big difference. Think about what children need. It's not expensive toys and big houses. It's you."

While there were many nurseries and playgroups with high quality staff who provided a good setting for learning, at poor quality daycare there was too much focus on physical factors – with staff "good at making sure nappies are changed and everyone's eating nicely" – but not enough on helping children develop emotional nad communication skills.

The research found social background made no marked difference, although children from more affluent families were reported to enjoy listening to stories and rhymes at a younger age than those from less well-off families.

Only 54% of the children who had problems received help from a speech and language therapist. Others received help from nursery and playgroup staff but 23% got no help at all.

• This article was amended on 4 January 2010. The headline's assertion has been changed to attribute it to Jean Gross rather than the YouGov poll, and a phrase inserted to clarify that the poll was commissioned by Gross.