Three strangers, 2 females and 1 male each made 1 home visit to 60 boys and girls within a maximum of 10 days. The subjects were equally divided as to sex, and chosen to fit into 3 age groups of 8, 10 and 12 mo. A significant number of children were stable in their responses to strangers; but only the positive response was stable. The negative response was unstable. The findings prove untrue the implicit assumption made in the literature that a child''s response to an investigator on the particular day of the investigation is the child''s consistent response to strangers for that particular period of his life. No evidence was found for a phase during which infants invariably fear strangers. The results necessitate a re-evaluation of the traditional guideposts of infant''s social and emotional development.