Violation of infants' expectations as a method of diagnosing levels of object concept

This study was designed to investigate the development of object identity in infants at ages corresponding to Piaget's Stages IV, V, and VI. Thirty-six babies were used as subjects, 12 each at 9-, 12-, and 18-months, divided equally between sexes. A game which involved tricking the infants by hiding one toy and having them find another was used to diagnose levels of object awareness. In order to determine the possible effects of toy preference on the infants' reactions to the game, two kinds of tricks were performed. One condition involved transforming a preferred toy into a nonpreferred one, and the second condition the reverse order. At least two tricks were performed on each subject to observe the effects of toy order on the same child. Six subjects at each age level, half boys and half girls were randomly assigned to one of the two conditions. It was expected that the older infants would show high levels of object concept, i .e., would react to the tricks with surprise and a concern over what caused the toys to disappear; the youngest infants would show no puzzlement and simply play with toys with no awareness of tricks; the 12-month-olds would show varying degrees of puzzlement and a focus on the toy that appeared or disappeared with no concern for cause. With respect to the effects of the toy preference, it was hypothesized that the oldest group would be puzzled regardless of toy value, the 12-month-old group would be more puzzled when the trick was against them, and the 9-month-olds would not be puzzled in either case. The major hypothesis that the infants' reactions to the transformation of objects would be age related was clearly confirmed, both in the case of the puzzlement reactions to the trick and the instrumental reactions that followed (p < .01). Thus, the 18-month-old tobies were showing the highest level puzzlement and instrumental reactions, the 12-month-olds were showing in between levels of puzzlement and instrumental reactions, and the 9-month- olds were showing the lowest levels of reactions. The hypothesis that the value of the toys involved would effect the subjects' reactions to the trick was also confirmed in the case of both the puzzlement and the instrumental reactions to the trick (p <.O5). Subjects on the whole were showing bigger reactions when the trick involved the transformation of a preferred toy into a nonpreferred toy. However, this trend held at all ages, and, therefore, the predicted relation of age to value was not confirmed. Since there were significant linear trends of age in each type of reaction to the trick, and since a Guttman Scalogram analysis showed that these reactions followed an order consistent with the levels of object awareness each age group possessed, it was concluded that an older age group would show more of the patterns of reactions expected to show up in this study. The infants showing more immature reactions than expected were found to conform to Piaget's sensori-motor Stages IV, V, and VI.