[Do adults' pretense signals promote pretend play behavior in children?].

Our goal in this study was to examine whether controlled pretense signal presentation by an adult promoted pretend play behavior in toddlers. Seventy-two Japanese toddlers (24 toddlers in the 18-month-old group, 24 toddlers in the 24-month-old group, and 24 toddlers in the 30-month-old group) participated in one of two experimental conditions: signal and signal-less. In the signal condition, the experimenter presented children with pretend play behaviors (eating, drinking, pouring, and wiping) accompanied by a smile, speech including sound effects, and gazing. In the signal-less condition, the experimenter presented only pretend play behavior with a neutral facial expression without speech or gazing. For each child, we coded the number of pretend play behaviors and recorded the number of seconds the toddler engaged in the behavior. Results indicated that 18- and 24-month-old toddlers' pretend play behavior lasted longer in the signal condition than it did in the signal-less condition. However, the 30-month-old toddlers showed no difference in pretend play behaviors between the signal conditions. In sum, adults' pretense signals promoted pretend play behavior only in 18- and 24-month-olds, and not in 30-month-olds.