What is Autism?
More accurately called autism spectrum disorders for its wide range of symptoms and degrees of severity, autism is a grab bag of developmental problems affecting a child's ability to communicate and interact with others. It also causes kids to engage in repetitive behaviors, such as hand slapping and rocking. And sometimes autistic children become fixated on certain objects for hours, like the wheels of a toy car. A child can have many delays in the areas of communication, social interaction, and repetitive behavior -- or a few quirks that are considered autistic but don't add up to a full-blown diagnosis. Some kids show signs well before 12 months; others appear to develop normally, then suddenly regress at around 18 to 24 months. And for reasons unknown, autism is four times more common in boys.
Over the past two decades, autism rates have jumped tenfold. But no one is certain what's behind the spike. It's possible that more cases are being diagnosed because experts better understand autism. And we do know there's a strong genetic component -- kids who have an autistic sibling have a 15 to 20 percent higher risk of developing it. Among identical twins, if one has autism, there's a 90 percent chance the other will also be autistic.
Meanwhile, one factor that's been thoroughly disproven is any connection with vaccines. Numerous studies show that unvaccinated kids don't have a lower risk for autism than those given vaccines (with or without the preservative thimerosal).