“Stranger” Distress: Confirmation of a Developmental Shift in a Longitudinal Sample

Abstract

Whether infants normally develop distress to a stranger in the second half year of life is an important and apparently unresolved question in view of recent criticisms of prior research. To answer the question whether there is a developmental shift in infants' reactions to a standardized approach by a stranger, a longitudinal study was carried out of 14 infants tested during monthly home visits from months 4 through 12. Films of facial expressions were rated to establish the presence and absence of distress. Positive as well as negative facial expressions were recorded, and attention was given to details of behavioral reactions rather than to pooled indices of behavior. All infants tested showed distress at some point in the first year with a mean age of onset of 8 months. Distress tended to persist on subsequent testings. The developmental course of the infants' reactions involved two opposite functions: a decline in positive responding and an increase in negative responding in association with the stranger's approach during the second half of the first year. Thus, we concluded that a developmental shift was found, and, in conjunction with other recent work contrasting reactions to mothers, the shift was interpreted as due to reactions to strangers.