Toddlers who attend nurseries for 35 hours a week are more likely to display anti-social behaviour and be worried and upset, research for the Government suggests.

A study of a £370 million Government initiative to expand childcare provision found that the longer children were left in childcare facilities, the more disruptive they became.

Those in nurseries or similar centres for more than 30 hours or three days a week were more anti-social, more likely to tease other children and call them names, or to be bossy and want their own way, the report suggested. Youngsters who attended for 35 hours or more per week displayed yet more “worried and upset” behaviour.

The research for the Department for Education and Skills (DfES) did nonetheless show that the impact of long hours in childcare was a mixed and complex question, with other children surveyed for the study displaying a number of positive effects, including an increase in confidence and greater sociability with peers.

“The children rated as more cooperative, sociable and confident were not usually the same children who were rated as more anti-social or worried/upset,” the report noted. “Thus, some children showed increased positive behaviours with time spent in group care while others showed increased negative behaviours.

“The age at which children started attending nursery did not significantly affect their behaviour but the more months they had been attending the more likely they were to display anti-social behaviour,” the report added.

The research - led by academics at Oxford University and other leading research centres - came as teachers warned that young babies risked being “institutionalised” by the state because more mothers were being encouraged to return to work.

The study also found that putting toddlers in mixed age groups had both a good and bad influence on their development.

Youngsters under three and a half years’ old were more upset if they were in groups with older children.

“Mixed age rooms, when younger children mix with children aged four and over, offered higher quality educational provision for young children, but were not always beneficial for their emotional adjustment.”

The wider-ranging study examined the effects of the government’s Neighbourhood Nurseries initiative, which was set up in 2001 to increase the provision of childcare in some of the poorest parts of the country.

The scheme was funded with Lottery money and Government grants and aimed to help parents in disadvantaged areas back into jobs.

The academics analysed profiles for 810 children and their families in 100 nurseries to assess the impact of spending time in childcare on toddlers’ development.

A spokesman for the DfES said previous studies had shown that “good quality early education befits children's all-round development and that these benefits last until at least age ten.”

He added: “Findings in this study on the impact on children's social and emotional development of spending 30 hour per week in childcare are mixed with evidence of positive impact for some children as well as small negative impact for others.

“The study also found that good quality provision - better average qualification levels of staff and presence of a qualified teacher, significantly improves levels of social and emotional development and reduces the risk of children developing negative behaviours. Our drive to improve skills and qualifications is therefore the right way to tackle this issue.”

The research emerged as members of the Association of Teachers and Lecturers warned that children who spend all day in childcare lose valuable time with their parents.

ATL’s annual conference in Bournemouth is debating a motion which “regrets that the drive towards full employment in an expanding economy will result in a greater institutionalisation of children“.

Cecily Hanlon, a teacher from Leeds specialising in early years who proposed the motion, said: “You can go into full day care when you’re three months’ old and virtually spend the whole of your childhood there.

“This concerns me very much because of the very long hours young children are spending in institutional group care, rather than with their families. “Babies are not actually babies very long.”

Times Recommends

• Donor organ allowed child’s own heart to heal
• Michael Jackson: Not the final chapter
• Brüno toned down for 15 rating