The role of familiarity and sound in the development of person and object permanence

A cross-sectional study investigated the development of search for objects that differed in animism (people vs. toys) and familiarity (mother vs. stranger, laboratory vs. home toy) in 37 infants at 6, 8 and 10 months. In different conditions, the objects either were (a) visible only prior to hiding, (b) audible during hiding, or (c) visible and audible prior to hiding, and then audible during hiding. Analyses of successful performance (criterion) and length of time infants took to reach criterion (latency) revealed the following. When infants were required to search for their mothers who interacted with them in a game of hide and seek, they performed better then when they were required to search for strangers or inanimate objects under similar conditions, especially during condition (c)