Koslowsky M, Levett C
J Clin Psychol. 1975 Jul;31(3):578-82. doi: 10.1002/1097-4679(197507)31:3<578::aid-jclp2270310347>3.0.co;2-r.
The Shipley-Hartford scales were given to 1,980 institutionalized addicts. Overall, results showed that addict IQs are about normal. Of all demographic variables analyzed, only education explained an appreciable proportion of the variance in scores (12%). There were indications that a relatively high number of addicts may have some intellectual impairment (41%). The latter results await further verification.
希普利 - 哈特福德量表被应用于1980名住院成瘾者。总体而言，结果显示成瘾者的智商大致正常。在所有分析的人口统计学变量中，只有教育程度解释了分数差异中相当大的比例（12%）。有迹象表明，相当数量的成瘾者可能存在一定程度的智力损伤（41%）。后一结果有待进一步验证。
