Primary school children and their parents are suffering from "deep anxiety" about modern life, according to a study of education in England.
The Cambridge-based Primary Review's report said the pressure of Sats tests dominated the last two primary years.
Researchers ran 87 discussions with groups of children, parents, teachers and others; 750 people took part.
The government said most children lived in better conditions than 10 years ago and rejected criticism of testing.
Primary Review director Professor Robin Alexander told BBC Radio 4's Today programme that young children faced a range of pressures.
"What people wanted to talk about was the stress of government tests, then life outside school, road safety, physical dangers, the sense young children are having to grow up too soon."
He also talked about the values children are subjected to, such as consumerism, individualism and materialism.
But he added that every generation had its stresses and some children had endured "unimaginable hardships".
Among those quoted in the Primary Review report are children themselves.
Children thought Sats tests were "scary", the report said
Many expressed concern about climate change, global warming and pollution, the gulf between rich and poor, and terrorism.
"Some were also worried by the gloomy tenor of 'what you hear on the news' or by a generalised fear of strangers, burglars and street violence," the report said.
But it added: "Where schools had started engaging children with global and local realities as aspects of their education they were noticeably more upbeat."
The children thought Sats tests "scary" but felt the results informed people about how they were doing.
Teaching assistants and parents complained, among other things, about "the pervasive influence of electronic media and gadgetry" and the "national obsession" with celebrity.
They also spoke of a "loss of childhood", the report said.
Many harked back to a golden age not so long ago "when they roamed the streets, fields and woods unsupervised and without regard for traffic or strangers, and had ample time to do so".
But Professor Hugh Cunningham, author of the book Invention of Childhood, told the BBC adults tended to "mythologise childhood" and that many of the concerns, such as consumerism and exam stress, had been around for a long time.
"I'm not at all surprised it showed anxiety about childhood," he said. "I would have been surprised if it hadn't."
He added it was important to look at the bigger picture whereby unequal societies had the most stressed children.
Sue Palmer, a former head teacher and author of Toxic Childhood, told the BBC that children were being sold the idea that "happiness is 'stuff'" and the availability of screen-based entertainment meant children were now "battery-reared".
"It is very worrying that children are not feeling safe, that they don't even trust their friends," she added.
The report concluded that prospects for the society and world that young children would inherit looked "increasingly perilous".
Prof Alexander said that, having travelled around the country to speak to people "inside and outside of education", he and his team had found "unease about the present and pessimism about the future".
Improving school "standards" - through tests and Ofsted reports - was not the same as raising the quality of education, he added.
"The health of a national educational system can't be fully captured by the term 'standards', critically important though standards are.
"Standards may have been too readily equated with quality."
He also told the Today programme that the schools themselves were the "beacons of light" in this report.
"They were there, a community within a community, holding to a very clear set of values and providing a network of support," he said.
A spokeswoman for the Department for Children, Schools and Families said: "We are committed to improving the lives of children and young people right across the country and we are making substantial progress.
"The vast majority of children go to better schools, enjoy better health, live in better housing and in more affluent households than they did 10 years ago.
"The government does not share the view that children are over-tested. Tests help parents and teachers monitor the progress of children and ensure they get the help they need."
Primary Review, an independent inquiry, will produce another 31 reports before publishing final recommendations in October 2008.
Clare Tickell of children's charity NCH said: "The findings of this report are a stark wake-up call to the government that urgent action must be taken to tackle this problem.
"We know from our own research the increasing importance of emotional wellbeing in childhood in determining life chances and later social mobility."