Research on similarity constructs (e.g., dyadic similarity, personality stability, judgment agreement and accuracy) frequently find them to be associated with positive outcomes. However, a methodological pitfall associated with common "overall similarity" indices, which we term the normative-desirability confound(NDC), will regularly result in similarity constructs apparently having more positive effects than they do in reality. In essence, when an individual is estimated to be similar to another person by common indices, this will strongly indicate that the individual has desirable characteristics. Consequently, the correlates of overall similarity indices can often be interpreted as indicating the beneficial effects of having desirable characteristics, without needing to attribute any additional salutary effect to similarity. We show that this confound is present in overall similarity estimates for a wide range of constructs (e.g., personality traits, attitudes, emotions, behaviors, values), how it can be accounted for, and discuss larger implications for our understanding of similarity constructs.

中文翻译：

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相似性估计值的相关性常常是误导性的：问题的性质和范围以及一些解决方案。

对相似性结构（例如，二元相似性，人格稳定性，判断一致性和准确性）的研究经常发现它们与积极结果相关。但是，与常见的“总体相似性”指标相关的方法上的陷阱（我们称之为规范可取性混淆）通常会导致相似性构造显然比实际构造具有更多积极作用。本质上，当通过共同指标估计某人与另一人相似时，这将强烈表明该人具有理想的特征。因此，总体相似性指标的相关性通常可以解释为表明具有理想特征的有益效果，而无需将任何其他有益效果归因于相似性。