Children with autism(孤独症) have difficulty with social skills and communication. They often act in limited and repeated ways and have what seem like unusual strong interests.

    Autism is more often seen in boys than girls. What causes it is not clear. Scientists are studying DNA and possible environmental influences.

    Doctors usually cannot confirm a diagnosis(确诊) of autism until a child is about three years old. Rebecca Landa is a researcher at the Kennedy Krieger Institute. Professor Landa wanted to find out what differences in development might be seen earlier. She led a new study that observed 235 babies between 6 and 36 months of age.

    “At six months of age, when you lay your baby on their back and you pull them by the arms gently into a seated place, the baby's head may nod back behind the shoulders, like poor head control. But that does not mean that the baby is going to have autism. It does mean the baby needs to have some exercises to help their body get stronger. And when the babies strengthen their bodies, they are better able to play with toys and also with people, which will help them have better outcomes.”

    By the time a baby is one year old, signs of possible autism include difficulty in using words and not looking eye-to-eye or reaching out to other people. By 14 months, the baby might smile less and use language less. However, Professor Landa says these signs can be very small and their children might be missed during a short health exam.

    “It's important for parents to pay attention to their children's development, and if they care about a child's development, they should listen to experts.”

    The earlier parents notice delays, she says, the sooner they can begin simple things that may help improve their children's development. For example, they can talk to the children about what they are doing, give opinions when the children show them something, and play simple games that keep the children's attention.