not that you want to be compared to a child or anything, and please take no
offense, but anyhow.....
my 3 yr old niece has mild cp.  it affects her right side. if she had her
way, she would never use her right hand/arm, it would be clenched up by her
chest.  her right leg does pretty well, you can barely tell she walks just a
little differently.  as an infant, she did the GI Joe crawl, she could never
get up on all fours (this was pre-diagnosis). and she didn't walk until she
was almost 2.  we all do exercises with her.
she too has a hard time controlling her laughter, and this is not just
because she's 3.  she does it when she's nervous, she'll get really silly
and laugh and laugh........making it difficult for her to complete whatever
task she's working on.  her parents supposedly see the anger thing, but i
think that's a reaction to her environment with them, and not related to the
cp.  she is very well mannered when she stays with the rest of the family.

:-)
tammy