In studies of children’s categorization, researchers have typically studied how encoding characteristics of exemplars contribute to children’s generalization. However, it is unclear whether children’s internal cognitive processes alone, independent of new information, may also influence their generalization. Thus, we examined the role that one cognitive process, forgetting, plays in shaping children’s category representations by conducting three experiments. In the first two experiments, participants (N_Exp1 = 37, M_age = 4.02 years; N_Exp2 = 32, M_age = 4.48 years) saw a novel object labeled by the experimenter and then saw five new objects with between one and five features changed from the learned exemplar. The experimenter asked whether each object was a member of the same category as the exemplar; children saw the five new objects either immediately or after a 5-minute delay. Children endorsed category membership at higher rates at immediate test than at delayed test, suggesting that children’s category representations became narrower over time. In Experiment 3, we investigated forgetting as a key mechanism underlying the narrowing found in Experiments 1 and 2. We showed participants (N_Exp3 = 34, M_age = 4.20 years) the same exemplars used in Experiments 1 and 2; then, either immediately or after a 5-minute delay, we showed children seven individual object features and asked if each one had been part of the exemplar. Children’s accuracy was lower after the delay, showing that they did indeed forget individual features. Taken together, these results show that forgetting plays an important role in changing children’s newly-learned categories over time.

在儿童分类的研究中，研究人员通常研究范例的编码特征如何有助于儿童的概括。然而，目前尚不清楚儿童的内部认知过程（独立于新信息）是否也可能影响他们的概括能力。因此，我们通过进行三个实验来研究一种认知过程（遗忘）在塑造儿童类别表征中所扮演的角色。在前两个实验中，参与者（N _Exp1  = 37，M_年龄 = 4.02 岁；N _Exp2  = 32，M_年龄 = 4.48 岁）看到实验者标记的新物体，然后看到五个具有 1 到 5 个特征的新物体与学习的范例不同。实验者询问每个物体是否与样本属于同一类别；孩子们要么立即看到这五个新物体，要么在延迟 5 分钟后看到。儿童在立即测试时比在延迟测试时认可类别成员资格的比例更高，这表明儿童的类别代表性随着时间的推移变得越来越窄。在实验 3 中，我们研究了遗忘作为实验 1 和 2 中发现的缩小范围的关键机制。我们向参与者（N _Exp3  = 34，M_年龄 = 4.20 岁）展示了实验 1 和 2 中使用的相同示例；然后，我们立即或延迟 5 分钟后，向孩子们展示七个单独的物体特征，并询问每个特征是否属于样本的一部分。延迟后，孩子们的准确度较低，这表明他们确实忘记了个别特征。总而言之，这些结果表明，随着时间的推移，遗忘在改变儿童新学到的类别方面发挥着重要作用。