A child's future really may be written in his hands-not in the creases of his palms but in the relative lengths of his fingers. A report just published in Developmental Medicine and Child Neurology suggests that people with autism have ring fingers that are abnormally long compared with their index fingers.

Children with autism have trouble interacting with other people. Both their verbal and their gesture-based comunication is poor, and they often have low intelligence. Early symptoms -a failure to point at things, follow the gaze of someone else, or engage in pretend paly- are often obvious by the tender age of 18 months. About one child in 500 suffers from the condition.

Two British researchers, who have studied what fingers can indicate about everything from fertility to sexual preference, have observed 72 autistic children and 23 with Asperger's syndrome, a related condition in wich the individual's intelligence is not affected.

The scientists photocopied the children's hands, and carefully measured the lengths of their fingers from the copies. They worked out the ratio of the length of the index finger to the length of the ring finger for each child, and compared it with those of their relatives.

The researchers found that autistic children had extremely long ring fingers compared with their index fingers. Children with Asperger's also had abnormal index-to-ring finger ratios, though less so than autistics. Even the unaffected relatives of the autistic children had ratios that differed significantly from the average lengths.