Stages of infant development, as illustrated by responses to the peek-a-boo game.

Abstract

Infants’ responses to different peek-a-boo stimuli presented by experimenters illustrate three infant non-mentalistic stages of development (Commons et al., 1998). Results showed that for the youngest infants (sensory and motor stage), almost any kind of interactive contact with another human (as long as it included vocalization with smiling and eye-contact) produced responses such as smiling. Between roughly 4 and 8 months (circular sensory motor stage), the specific version of the game that was played became important. Games that included hiding, coming out and saying peek-a-boo in an animated voice obtained maximum responses; games more divergent produced less responding. For older infants (sensory motor stage) games that diverged from the standard in specific ways could sometimes produce even higher rates of responsiveness, although this depended on the particular circumstances.