Thousands of five-year-old children are already at severe risk of disengaging from education when they start school, according to a new report.
A study by think-tank Demos found that more than one in 10 children start school without the behavioural skills they need to learn or build relationships.
Research among 15,000 young children found emotional problems, hyperactivity and difficulty making friends, which are all linked to under-achievement at school and risk truanting and exclusion, said the report.
The study was published ahead of new official figures which will show the number of young people in England not in education, employment or training, known as Neets.
Sonia Sodha, who wrote the Demos report, said: "One in 10 children lack the tools to benefit from education before they even get to the school gate.
"These nursery Neets show the same behaviour problems as older Neets, like difficulty making friends and bad behaviour."
The report called for early intervention to help young children and prevent them becoming unemployed and out of education.
The National Children's Bureau called for more help for young people, including affordable transport to travel to a job or college.
Deputy chief executive Barbara Hearn said: "The costs of travel for young people can be truly prohibitive to the fulfilment of basic needs, such as completing training, finding a job, engaging in positive activities or simply socialising.
"MPs must realise that the typical cost to a young person of a round-trip to college or a job centre can be the equivalent of an MP spending up to £60 per day of their income to travel only a short route to work. We fully support any efforts to create training or work opportunities for all young people but transport costs must reflect young people's lower earning capabilities."