Children with autism usually have less empathy with, and sympathy for, other people. Autism is usually diagnosed at around three years of old but children's empathetic responses to other people's distress usually develops between one and two. So, could this be used to provide an early diagnosis of, and interventions for, autism? A team of researchers from the University of California, Los Angeles tested this theory in a study of 158 children. One of the researchers pretended to hit their finger with a hammer and the children's responses were measured at 12, 18, 24 and 36 months, with the children being tested for autism at three. 103 of the children had brothers or sisters with autism and 14 were diagnosed with it at three. The children who went on to be diagnosed with autism paid less attention to, and showed less change in mood after, the researcher's 'accident' leading to hopes that such a test could be used to flag up those at risk of developing the condition.
Hutman, Ted ... [et al] - Response to distress in infants at risk for autism: a prospective longitudinal study Journal of Child Psychology and Psychiatry September 2010, 51(9), 1010-1020