Professor Priscilla Alderson, from the London's Institute of Education, is an expert in childhood studies. She says that some children who have been diagnosed as having a behavioural disorder, may just need to "let off steam".
She thinks that hyperactive disorders and mild autism are being diagnosed too often. After meeting with 27 autistic pupils, she said: "Of those, only two that I met displayed the lack of contact and absence of empathy which denotes true autism."
Professor Alderson goes on to say: "Children need the space and freedom to play, run and climb - without that, they are restless and come to be seen as abnormally 'hyperactive'."