Edward Tronick

Edward Tronick (1944) is an American developmental psychologist and professor at the University of Massachusetts. He is world-renowned for the 'Still Face Experiment' (1975), one of the most reproduced and cited studies in developmental psychology.

The Experiment: A mother interacts normally with her infant, a few months old, for 1-2 minutes —smiles, gestures, playful conversation—. Then, at a signal from the researcher, the mother suddenly adopts a still, expressionless face, not responding to the baby. The camera records the baby's response in the following 2 minutes.

What is observed: Within a few seconds, the baby actively starts to seek the mother's attention —smiles more intensely, makes broader gestures, vocalizes—. When the mother remains still-faced, the baby quickly transitions to states of protest —crying, turning away, hitting their chair—. Eventually, if the lack of attunement persists, the baby enters a state of disorganization —physically collapsing, disconnecting, glassy-eyed—. When the mother returns to her normal expression, there is a period of repair: the baby is initially confused, but the connection is generally reestablished.

Implications: The experiment empirically documented the real and immediate psychological impact of a lack of affective attunement in infants. It is the scientific basis for understanding why caregivers with severe depression, traumatic dissociation, or chronic emotional absence cause documented harm to infant development. It provides the foundation for the entire field of early relational trauma.