If you took child psychology or have a basic understanding of the stages of child development - you are probably familiar with the concept of modeling behavior. That's why a two year old will walk around in mommy or daddy's shoes - or, like my daughter, will put on a purse and walk around saying she's "going to work". That day, my father in law said she also went to the doctor, to the store and to the dentist.
So it shouldn't be news that children begin watching and emulating their parents for behavior cues at a young age. It's part of the reason why parents are encouraged to eat well, be active and read - if they want their children to follow their example.
I was reading outside yesterday evening while noggin (my son) and goose (my daughter) played. We have a big fenced in yard, sandbox, slide, etc. Since it's been warmer out, we've spent more time outdoors. (as a side note, we've also been able to spend more time gardening and working on the lawn. The kids help out, and enjoy the process, i.e. not eating the dirt or dandelions like they did when they were younger).
Noggin was playing with his toy engines, Thomas, Edward and Gordon on a table like surface. He was pushing them around (they hook together with magnets). All of a sudden, I heard him and goose saying sternly "No, Thomas, No! You're not supposed to do that! You are in time out!" Each of the engines received this lecture (Edward and Gordon were not excluded).
I think someone said "You stay here while we play on the slide". After a few seconds on the slide, they came back to the engines. There was some discussion of whether or not Thomas (and Edward and Gordon) could come out of time out. Both noggin and goose agreed that they could - and that was the end of that incident.
Everyone had told me that children were like little tape recorders (do people still know what tape recorders are?). But this incident brought it home to me - it was a little shocking for me to hear. From 0 - 5, children learn a tremendous amount, even from 0 - 2 they are constantly learning, watching, understanding their limits, the world they live in, how humans interact, what is acceptable and what is not acceptable. It should go without saying to readers here that this incident was obviously mimicking interactions my husband and I have had with our kids.
We use time out quite a lot, and find them effective. There is a lot of boundary testing in our house. We try not to be unreasonable, but there are certain things both children know they are not supposed to do. Hit one another or us, for example. Climb on the couch and move/touch the painting (climbing on the couch is a battle we choose not to fight).
At first we just let them sit in a chair in the same room for a minute or so. Now, we sometimes will put one or the other in their room - a time to cool off and be away from the action. Not for longer than a minute or so there either. They are enough of a deterrent to be meaningful, but not enough to be cruel or unusual.