Infants' Expectations in Play: The Joy of Peek-a-boo

Abstract

The role of expectations in infants' enjoyment of play was studied by observing their smiling, laughter, and eyebrow raises during a peek-a-boo game that contained occasional trick trials. In Experiments 1 and 2, 6, 7-, and 8-month-olds (n = 29) participated in a peek-a-boo game in which, on occasional “person-switch” trials, one adult hid and a second adult “reappeared” in his or her place. Infants in all age groups smiled less following person-switch reappearances than following normal ones, with the difference increasing with age. In Experiment 3, 7-month-old infants (n = 10) played a peek-a-boo game in which the adult occasionally reappeared in a different location. Smiling decreased for “location switches” just as it had for person switches. Infants in all age groups were more likely to exhibit eyebrow raises following trick reappearances than following normal ones. These findings suggest that infants as young as 6 months have expectations about the identity and location of a returning person, that conformity to these expectations contributes to infants' enjoyment of games such as peek-a-boo, and that infants of this age may not yet enjoy deviations from their expectations. Implications are discussed for theories of playful enjoyment, for the cognitive antecedents of positive affect, and for cognitive development.