Here is where talk is not just about telling other people things, but to tell yourself things. And you see this in working with parents and being a parent, that trying to talk down to a two- or three-year-old who's having a temper tantrum doesn't work.
As much as we'd like to use inductive discipline and talk to the child, when a two-year-old is very upset, you really have to hold him or distract him, take him away from the situation. You can't really talk children out of their emotions. In fact, it's very hard to do that with adults many times. [laughs] But it's not possible with two-year-olds, and that's because when they're upset and their emotions are coursing through their brain, the cognitive capacity to listen to language or to talk to themselves about what's happening is just not present.
Somewhere between age three and four, this magic change begins to occur in which children now begin to use language to represent things to themselves as they're actually happening. And a perfect example of this is in our research. We often use what's called the "strange situation," which is a laboratory situation in which the mother and the child are separated. The mother plays with the child and then leaves the room, and the child is in the room alone. And it's often upsetting. The heart rate goes up, and some are concerned where their mother is, even though they know she's coming back. Some of them will begin to get a little weepy. But oftentimes they'll look in the one-way mirrors we're using to film through, and then they'll say to themselves something like, "My mommy is coming back." Or they'll start to sing to themselves. This is a fundamental aspect of play therapy, as children can now begin to play representationally to manage their emotions.
Go read the whole article -- it is fascinating.