One in ten children who are severely autistic at the age of three outgrow many of the disorder's symptoms by the time they are eight, according to a new study.
The report published today in American journal Pediatrics showed one reason could be the child's social economic background, with 'bloomers' tending to come from better off families.
Study researcher Christine Fountain, a postdoctoral fellow at Columbia University in New York City, said the biggest improvers may have benefited because their parents were able to afford access to better quality treatment.
She said: 'These socio-economic disparities suggest that equal access to early interventions and services for less advantaged children is going to be really vital.'
The records of almost 7,000 Californian children with autism between the ages of two and 14 were analyzed for the study.
Fountain said an autistic child with a low score on the social scale would not be able to make friends or socialize
The best performers could 'initiate one-on-one interactions with both peers and others in familiar and unfamiliar settings, initiate and maintain friendships, and not need encouragement to participate in social activities'
Meanwhile, when it comes to communicating, the most severely autistic children may not be able to even make sounds, but at the upper end they would have a broad vocabulary and could take part in complex conversations.
Researchers discovered many autistic children showed improvements between ages three and eight, but the 'bloomers' astounded them by progressing from the most severely affected to some of the highest functioning during this time period.
In spite of their startling improvement, many still displayed classic symptoms of autism such as an inclination to rock back and forth.
They were more likely to have white mothers with a high school education and who come from a higher socio-economic class.
Researchers did not have any information about their fathers.
Tamar Apelian, staff psychologist at the autism evaluation clinic at the University of California, Los Angeles, was not surprised the study found socio-economic background could play a part in America.
He told msn: 'What’s tricky is being able to navigate the system to get the therapy. The parents who do this seem to have more means and they can hire an advocate or a lawyer.'