Smiling response

The smile with which an infant of about two to three months greets a human face seen from the front and in motion. René Spitz and Katherine Wolf found that at this age it is set off by a configuration of forehead, eyes and nose rather than by a particular person, and will be given even to a mask, while in the second half of the year it becomes reserved for familiar people. Spitz made it the indicator of the first organizer of the psyche: it marks the infant's shift from responding to inner bodily stimuli to perceiving the outside world, and the arrival of the precursor of the object, the stage before the mother is recognised as a person in her own right.