DOCTOR EDWARD TRONICK: Babies this young are extremely responsive to the emotions, and the reactivity, and the social interaction that they get from the world around them. This is something that we started studying 34 years ago, when people didn't think that infants could engage in social interaction.
In this "Still Face" experiment, what the mother did was, she sits down and she's playing with her baby who's about a year of age.
MOTHER: Are you my good girl?
EDWARD TRONICK: And she gives a greeting to the baby, the baby gets a greeting back to her. This baby starts pointing at different places in the world, and the mother's trying to engage her and play with her. They're working to coordinate their emotions and their intentions, what they want to do in the world. And that's really what the baby is used to.
And then we asked the mother to not respond to the baby. The baby, very quickly, picks up on this, and then she uses all of her abilities to try and get the mother back. She smiles at the mother, she points, because she's used to the mother looking where she points. The baby puts both hands up in front of her and says, what's happening here? She makes that screechy sound at the mother, like, come on, why aren't we doing this?
Even in this two minutes, when they don't get the normal reaction, they react with negative emotions; they turn away, they feel the stress of it, they actually lose control of their posture because of the stress that they're experiencing.
[BABY CRYING]
MOTHER: OK, [INAUDIBLE]. I'm here. And what are you doing? Oh, yes. Oh, what a big girl.
EDWARD TRONICK: It's a little like, the good, the bad, and the ugly. The good is that normal stuff that goes on, that we all do with our kids. The bad is when something bad happens, but the infant can overcome it. After all, when you stop this Still Face, the mother and the baby start to play again. The ugly is when you don't give the child any chance to get back to the good. There's no reparation, and they're stuck in that really ugly situation.