There is no adequate explanation for this imbalance in the sex ratio, though it must be recognized it is also true for other developmental disorders of early childhood such as learning disabilities and attention deficit disorder.

CNN: How girls and boys differ when it comes to autism

Clinton also shelved his campaign commitment to deliver a middle class tax cut upon learning the size of the deficit.

CNN: Commentary: Obama's 100 days of problems?

In it, the therapist describes the child as an apparently "typical 5-year-old by temperament and interests" with no history of mood swings, irritability, depression, attention deficit disorder, learning issues or other problems.

CNN: STORY HIGHLIGHTS

Successful men with learning difficulties such as dyslexia, autism and attention deficit disorders, including some she met as children, explain how an unpromising start can sometimes act as a springboard.

ECONOMIST: Men, women and work

However, golf requires both power and precision -- which Phelps, who was diagnosed with attention deficit disorder as a child, is slowly learning to combine.

CNN: Post Olympics life: Michael Phelps' golf growing pains