What age to start with the naught spot?

[spring]

Just wondering what age children can start understanding the threat of the naughty corner/mat/chair etc'

[~Emmylou~]

Our DD didn't "get it" until a couple of months after she turned two.

We actually tried at 18 mths but it was pretty obvious she wasn't ready. She wouldn't stay there, she looked at us like we were from Mars - she had no idea WHAT we were prattling on about nor did she care. When she came out and we tried to talk to her you could tell there was no "connection" there between what she'd done 5 minutes ago and what the conversation was about after time out.

Now she knows why she's there, and when she comes out she will tell us what she did to get herself there. So she "gets it" now. It works really effectively now.