Wong, Kourtit and Nijkamp address a persistent contradiction between urban planning research, which often attributes substantial wellbeing effects to the built environment, and psychological research that assigns comparatively modest explanatory power to geographical circumstances. Their meta-analysis synthesises evidence from 54 studies covering 29 neighbourhood interventions and then uses meta-regression to examine intervention type, environment, population, duration and research design. The iconic finding is not a single universal effect but differentiated efficacy: place-based interventions are more likely to produce short-term mental-health and wellbeing benefits than people-based mobility programmes, while outcomes vary across subgroups and environmental dimensions. The theoretical contribution is to reposition neighbourhood effects as conditional rather than deterministic. Methodologically, the paper combines systematic review and quantitative synthesis to expose heterogeneity hidden by isolated studies. It bridges urban planning, wellbeing economics, public health and environmental psychology, providing a rigorous framework for evaluating how spatial interventions work differently across populations and contexts.