Green space mitigates aggression : evidence from population- and individual-level analyses

Abstract

Growing studies demonstrate not only the physical but also psychological benefits of the natural environment, especially green space. Chapter 1 provides an overview of the psychological impacts of green space. Anchoring on the attention restoration theory and the stress reduction theory, the review focuses on cognitive and emotional improvements. Building on recent research on the influences of green space on interpersonal relationships, this thesis investigates the effects of green space on aggression—an adverse form of interaction—using population-level crime data alongside individual-level survey and experience sampling data. Chapters 2 and 3 report two studies that utilized remote sensing imagery and police-recorded crime data to examine the relationship between green space and violent assault rates at the population level. Chapter 2 highlights the importance of conducting separate investigations on domestic violent assaults, which provides a more accurate representation of aggressiveness than non-domestic violent assaults due to the reduced surveillance effect. Green space fractional coverage and population-weighted exposure both demonstrate negative associations with both domestic and non-domestic violent assault rates. Since numerous studies consistently report a close association between temperature and violence, Chapter 3 investigates the potential moderating role of green space in the relationship between temperature fluctuation and violence occurrence. Measures of the spatial amount of green space (fractional coverage and population-weighted exposure) exhibit significant moderation effects for domestic violence. The extent of seasonal variation in vegetation emerges as a robust moderator for both forms of violence. Chapter 4 reports a study that examined the moderation effect of green space on the influence of regional temperature on domestic violence at the individual level using secondary large-scale survey data in South Asia. Results uncover two significant two-way moderation effects of both the spatial amount of green space and the seasonal variation in vegetation on the association between regional temperature and the occurrence of domestic violence. A larger spatial amount of green space is effective in mitigating domestic violence in regions with moderate temperatures, and greater seasonal variation in vegetation acts protectively in cooler and hotter areas. Chapter 5 reports a study that used secondary experience sampling data to investigate momentary emotions associated with interpersonal interactions in green space. The findings indicate that being in green space may reduce levels of aggressive emotions and increase levels of prosocial emotions. It supports the pathway by which green space mitigates aggression through the enhancement of emotions related to interpersonal interactions. Chapter 6 summarizes the findings across the four empirical studies and discusses their implications. Results from the four studies consistently suggest the protective effect of green space against aggression. The moderation effect of green space on the relationship between temperature and violence holds potentially significant implications for managing aggression in the face of climate change. This thesis employs a combination of population-level and individual-level data to highlight the critical role of green space in mitigating aggression.