Department of Psychological Sciences.
Department of Psychology.
Psychol Rev. 2019 Nov;126(6):865-879. doi: 10.1037/rev0000156. Epub 2019 Aug 15.
We explore the implication of viewing a psychological theory as the logical conjunction of all its predictions. Even if several predictions derived from a theory are descriptive of behavior in separate studies, the theory as a whole may fail to be descriptive of any single individual. We discuss what proportion of a population satisfies a theory's joint predictions as a function of the true effect sizes and the proportion of variance attributable to individual differences. Unless there are no individual differences, even very well replicated effects may fail to establish that the combination of predictions that have been tested accurately describes even one person. Every additional study that contributes another effect, rather than strengthening support for the theory, may further limit its scope. Using four illustrative examples from cognitive and social psychology, we show how, in particular, small effect sizes dramatically limit the scope of psychological theories unless every small effect coincides with little to no individual differences. In some cases, this 'paradox' can be overcome by casting theories in such a way that they apply to in a target population, Rather than relegating heterogeneity to a nuisance component of statistical models and data analysis, explicitly keeping track of heterogeneity in hypothetical constructs makes it possible to understand and quantify theoretical scope. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
我们探讨了将心理学理论视为其所有预测的逻辑合取的含义。即使从一个理论中得出的几个预测在单独的研究中描述了行为，但整个理论可能无法描述任何一个个体。我们讨论了理论的联合预测在多大程度上满足了人口的需求，这取决于真实的效果大小和归因于个体差异的方差比例。除非没有个体差异，否则即使是非常好的复制效果也可能无法证明已经测试过的预测组合准确地描述了一个人。每一项增加的研究都贡献了另一个效应，而不是加强对理论的支持，反而可能进一步限制其范围。我们使用认知和社会心理学中的四个说明性示例，展示了特别是小的效果大小如何极大地限制了心理学理论的范围，除非每个小效应都与几乎没有个体差异相吻合。在某些情况下，通过以这样的方式构建理论可以克服这种“悖论”，即它们适用于目标人群中的 ，而不是将异质性归为统计模型和数据分析的麻烦部分，明确跟踪假设构念中的异质性使得理解和量化理论范围成为可能。(PsycINFO 数据库记录(c)2019 APA，保留所有权利)。
