A dislike or mistrust of unfamiliar people, often beginning around a baby's eighth or ninth month. Wariness of strangers may last a short while or many months; some babies may never exhibit a fear of strangers.
Wariness of strange people and places, shown by some infants during the second half of the first year. (167)
Normal emotional response of infants occurring around seven months upon hearing, seeing or being picked up by an unfamiliar person.