Piagetian liquid overconservation was investigated in four grey parrots (Psittacus erithacus). Birds tracked the larger of two quantities that had undergone various manipulations. Experiment 1 involved controls to ensure birds could track movement of the quantities, including direct and diagonal cross-transfers. All birds succeeded. In Experiment 2, different amounts in the same transparent or opaque containers were transferred into containers rigged such that amounts then looked equal. All birds chose the larger amounts after transformation when initial cups were transparent, but were random or had consistent side preferences when initial cups were opaque (thus obscuring quantity differences), showing that they used inferential, not perceptual, information, and that no extraneous cues existed. In Experiment 3, two birds saw different amounts from same-sized transparent or opaque containers transferred to containers of different sizes, rigged such that resultant amounts appeared to fill both cups and in which lesser amounts appeared greater on some trials. The older bird demonstrated full use of inferential abilities; he succeeded in all tasks when initial cups were transparent but, again, had consistent side preferences with initially opaque cups. The younger succeeded in the direct transfers with transparent initial cups but was random or showed a side preference on diagonal-transfer tasks and on all the tasks with opaque initial cups. However, she had no preference for the cup that appeared fuller, suggesting she did not use perceptual cues. Overall, grey parrots appear to understand the constancy of liquids undergoing physical transformation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

中文翻译：

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灰鹦鹉（Psittacus erithacus）的Piagetian液体过度保存。

在四个灰鹦鹉（Psittacus erithacus）中研究了Piagetian液体过度保存的情况。鸟类追踪了经过各种处理的两个数量中较大的一个。实验1涉及控制，以确保鸟类可以跟踪数量的运动，包括直接和对角线交叉转移。所有的鸟都成功了。在实验2中，将相同透明或不透明容器中的不同量转移到装配好的容器中，然后看起来相等。当初始杯透明时，所有鸟类在转化后都选择较大数量的鸟，但是当初始杯不透明（从而掩盖数量差异）时，它们是随机的或具有一致的偏好，这表明它们使用了推论而非感知的信息，并且没有无关紧要的提示存在。在实验3中，两只鸟从相同大小的透明或不透明容器中看到了不同数量的鸟，这些鸟被转移到不同大小的容器中，并进行了操纵，使得最终的数量似乎能填满两个杯子，而在某些试验中，数量更少的鸟看起来更大。年龄较大的鸟表现出充分利用推理能力的能力。当最初的杯子是透明的时，他成功地完成了所有任务，但是与最初不透明的杯子相比，他仍然具有一致的侧面偏好。较年轻的孩子用透明的初始杯子成功进行了直接转移，但在对角转移任务和不透明的初始杯子的所有任务中表现出随机性或偏爱。但是，她没有选择看起来更饱满的杯子，这表明她没有使用知觉提示。总体而言，灰鹦鹉似乎了解正在经历物理转变的液体的恒定性。