AT A MEETING of the Society for Research in Child Development in 1975, the psychologist Edward Tronick presented a paper that would fundamentally change how we understand infant cognition and human attachment. Dr. Tronick and his team conducted an experiment in which mothers were instructed to play with their babies for a short period and then abruptly allow their faces to go blank. By “blank” I mean chillingly unresponsive, without affect. In an interview about this “Still-Face Experiment,” Dr. Tronick describes what happens next to the infant:
She uses all of her abilities to try
and get the mother back. She
smiles at the mother. . .. 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
