Spitz H H, Stephens W E
Am J Ment Defic. 1976 Sep;81(2):197.
An error in calculation of MAs of the moderately retarded subjects in the above study raises significant questions about the findings that their use of action concepts is less than that of mildly retarded subjects of the same MA. Their reduced performance may instead be attributable to some unknown extent to their lower MA.
上述研究中中度智力迟钝受试者心理年龄（MA）计算上的一个错误，引发了关于以下研究结果的重大疑问，即他们对动作概念的运用比相同心理年龄的轻度智力迟钝受试者要少。相反，他们表现较差在某种未知程度上可能归因于其较低的心理年龄。
