Haslam S A, Oakes P J, Turner J C, McGarty C
Department of Psychology, Australian National University, Canberra.
Br J Soc Psychol. 1995 Jun;34 ( Pt 2):139-60. doi: 10.1111/j.2044-8309.1995.tb01054.x.
Using the Katz-Braly checklist subjects (N = 65) assigned five traits to a national group and estimated the percentage of group members who had those traits. This was either an in-group (Australians) or an out-group (Americans), and subjects either judged that group alone (one-group conditions) or also estimated the percentage of people from the other nation (the United States or Australia, respectively) who had those same traits (two-group conditions). Across one-group conditions there was a significant out-group homogeneity effect with traits being seen to apply to more Americans than Australians, but there was no such effect across the two-group conditions. These findings were predicted on the basis of self-categorization theory's analysis of the role of comparative context in determining level of social categorization. Across two-group conditions non-stereotypic traits were also applied to fewer in-group than out-group members. This result suggests that trait favourableness is an important normative-motivational determinant of perceived homogeneity. A second experiment (N = 297) confirmed this point through an additional manipulation of the favourableness of checklist traits. This study also replicated the effect for comparative context. Implications for the analysis of social categorization, perceived group homogeneity and stereotyping are discussed.
使用卡茨 - 布拉利清单，受试者（N = 65）为一个国家群体赋予五个特质，并估计具有这些特质的群体成员的百分比。这一群体要么是内群体（澳大利亚人），要么是外群体（美国人），受试者要么仅对该群体进行判断（单群体条件），要么还估计另一个国家（分别为美国或澳大利亚）具有相同特质的人的百分比（双群体条件）。在单群体条件下，存在显著的外群体同质性效应，即人们认为这些特质适用于更多美国人而非澳大利亚人，但在双群体条件下不存在这种效应。这些发现是基于自我分类理论对比较背景在确定社会分类水平中的作用的分析而预测的。在双群体条件下，非刻板印象特质应用于内群体成员的数量也少于外群体成员。这一结果表明，特质的有利程度是感知同质性的一个重要规范 - 动机决定因素。第二个实验（N = 297）通过对清单特质的有利程度进行额外操纵证实了这一点。本研究还重复了比较背景的效应。讨论了对社会分类、感知群体同质性和刻板印象分析的启示。
