Oct. 23, 2008 -- Question: Is it more likely for boys or girls to be diagnosed with autism, and do we know why?
Answer: About four or five boys are diagnosed with an autism spectrum disorder for every girl who is diagnosed.
We don't know why there is this distinctive sex ratio in autism as there is in many other early developmental disorders. Some people think it could have to do with differences in the early brain growth and development between boys and girls.
As more is learned about the genetic origins of autism, it's possible that other reasons will be discovered.