What the general factor of psychological problems is-And is not.

Abstract

This article discusses the general factor of psychological problems. Hundreds of published studies have advanced understanding of the general factor of psychological problems, but confusion still surrounds the hypothesis. This partly results from critics conflating the hypotheses with those of other authors, but they have created confusion ourselves by stating two hypotheses involving the general factor, which they better differentiate here. In the psychometric general factor hypothesis, the general factor is simply the term in bifactor models that quantifies the variance shared by all measured psychological problems, whereas two or more specific factors are defined by orthogonal pools of variance shared only by items loading on each specific factor. Although the psychometric bifactor model is sometimes viewed as an alternative to taxonomic models based on correlated factor models, it is not. Those models properly describe the overlapping dimensions of psychological problems experienced in everyday life. Because bifactor and correlated factors models serve different purposes, there is no need to compare their fits. The separate hierarchical causal hypothesis is that correlations among all problems that define the general factor result from some of their causes and mechanisms being directly or indirectly shared, whereas the specific factors are the result of other causes being shared by subsets of problems. There is growing evidence that some genetic and environmental causes-and their attendant psychobiological mechanisms-are shared to varying degrees with essentially all psychological problems. Other independent causes and mechanisms influence only subgroups of psychological problems (e.g., internalizing problems), and still others are problem-specific. At this point, the evidence is informative but only correlational. Nonetheless, there is evidence that some measured variables of potential causal and mechanistic significance are empirically correlated with the general factor term in bifactor models, whereas other risk factors are correlated with the terms for the specific factors of psychological problems. Other studies have shown that the general factor of psychological problems is robustly correlated with important psychological constructs. (PsycInfo Database Record (c) 2025 APA, all rights reserved).