Well, that's not what they meant to say. But it's what they said in this article suggesting children don't understand sarcasm until age 5, and don't appreciate it as humor until age 10. I sure know I was using it by age 5, and found it funny in movies at around the same age. And I know several of my niece's Nickelodian shows utilize sarcasm. I can only conclude what I wrote in the headline, then...