Parents with autistic children generally describe the descent into the disorder as sudden and dramatic. But according to new research, the social disengagement of autism begins from the sixth-month mark. The findings of the study, published in the Journal of the American Academy of Child and Adolescent Psychiatry, run counter to the observations of parents, most of whom report the first signs of autism in the second year of life. The California researchers behind the study observed the development of 50 babies, half of which went on to develop autism. In those who developed autism, the California researchers found that the telltale signs of social disengagement evaded 83 per cent parents in the first year they were happening.