When do kids "get" jokes?

[LissyGlitter]

DD is being hilarious at the moment, she says "knock knock, who's there?" and laughs at herself. She's 2.3. I've tried teaching her "doctor, doctor who, how did you know my name?" but she doesn't get it. Her sense of humour still mainly consists of hiding her face then uncovering it and laughing hysterically...somehow I don't think she'll be a leading sitcom writer when she's older...

Ds was about 5 when he really and truly started getting jokes by himself. Up till then it was visual humour that made him laugh. He is 6 now and will often wake up in the morning and tell me a joke that is actually funny.

Why did the chicken cross the playground
To get to the other slide.

How do bees get to work
They take the buzzzzzzzzzzz

I want to tell you a joke about the ceiling
Oh, forget it, it'll just go over your head

I was watching TV when the lights went out
I was de-lighted

Are this weeks standup routine.