The relationship's the thing: Commentary on Caspi et al. (2026)

To provide partial support for the "p" factor, Caspi et al. (see record 2026-80066-001) provide meta-analytic and large sample data evidence of assortative mating for various forms of psychopathology. From this, they conclude that assortative mating leads to transdiagnostic risk for symptoms of mental illness in offspring. In this commentary, I focus on why individuals assortatively mate for psychopathology, even in the face of evidence that they do not assort for similarity of personality. Personality is firmly entrenched as a correlate of mental disorders, to the point of being included in structural models of psychopathology. Individuals with different personalities end up in relationships that become distressed and trigger psychopathology; each partner's unique personality traits shape the form of psychopathology they experience. As Caspi et al. argue, interventions for mental illness do need to move beyond the traditional therapist-patient model to incorporate spouses and other family members. There may be a segment of the population, however, because of low socioeconomic status, prone to marital distress and psychopathology and more likely to benefit from financial support than psychological interventions. (PsycInfo Database Record (c) 2026 APA, all rights reserved).