Environmental influences on neuroticism in adulthood: A systematic review

Behavioral-genetic studies show substantial non-genetic influences on variance of neuroticism within a population. Longitudinal studies show a small but steady drop in test-retest correlations with increasing time intervals. This suggest environmental effects on neuroticism, but a systematic overview of which environmental determinants account for change in neuroticism is lacking. We review (specific or unique) environmental influences that modify the neuroticism setpoint in adulthood and therewith individual life trajectories. Results are interpreted in light of the so-called ‘mixed model’ in which within-person changes in neuroticism are subdivided over short term perturbations around the setpoint of neuroticism versus more persistent changes in the setpoint itself. To account for genetic confounding and shared environmental influences studies of monozygotic (MZ) twin pairs discordant for neuroticism and longitudinal studies that report on environmental factors that predict within-individual change in neuroticism are reviewed. Our results indicate that the neuroticism setpoint is consistently touched by experiences that affect central aspects of one’s identity and status, mainly role transitions as partner (marriage/divorce) and employee (job loss/promotion). Especially interpersonal stress, conflict, and major events that were unpredictable, uncontrollable, unexpected, undesirable, and ‘off time’ from a life history perspective were followed by changes in neuroticism that persisted more than six months, which suggest setpoint change. Most change after severe SLEs persisted over a decade. Long-term and detailed studies are required to elucidate the details of the ‘mixed model’ of change in neuroticism. An understanding of the specifics of the events that lead to persistent changes in neuroticism may enable us to craft prevention strategies to tackle the vulnerability for mental disorders inherent in high neuroticism, rather than to wait for their manifestation.