Sustaining Social Interaction in Public Squares After Dark: A socio-physical perspective on the lighting-behaviour relationship

Title and subtitle:Sustaining Social Interaction in Public Squares After Dark: A socio-physcial perspective on the lighting-behaviour relationshipAbstractAs everyday life-spaces, public squares are essential for supporting social interaction and thereby contributing to individuals’ wellbeing and quality of life. The provision of safe, accessible, and inclusive public squares is imperative for sustainable urban development of cities and communities. After dark, electric lighting is necessary for sustaining activities, including social interactions, in public squares. Lighting may support user needs such as accessibility, reassurance, comfort, restorativeness, and atmosphere, all of which are essential for facilitating movement, enabling stationary activities, and encouraging social interaction in public squares after dark. In countries at northern latitudes, where daylight hours are limited in winter, lighting design is instrumental in sustaining social life in public squares after dark. However, the impact of lighting on people’s experiences of public squares after dark, and how specific lighting characteristics may influence behaviouraloutcomes in such spaces, is poorly understood.This thesis aims to investigate the relationship between spatial light characteristics, perceived atmosphere, and social interaction in public squares after dark.The thesis expands the knowledge on the role of lighting in sustaining social interaction in public squares after dark. By adopting a socio-physical perspective on the lighting-behaviour relationship, it proposes a conceptual model to further our understanding of human-environment transactions in public squares after dark.The socio-physical conceptual model illustrates the transactional relationship between the individual, the environmental setting, the environmental appraisal, and the behavioural outcome. It stipulates that the individual’s appraisal, and therefore her behaviour, are influenced by the lighting conditions. The model was applied in four empirical field studies that were conducted in two differently illuminated public squares (Kirseberg Square and Lindeborg Square) in Malmö, Sweden. Study 1 (S1) and Study 2 (S2) focused on the behavioural outcome using direct, structured observations to compare user behaviour in daylight (DL) and in electric lighting (EL) after dark, in the two squares with dissimilar lighting conditions. S1 investigated movements and stationary activities and tested whether any change in these behaviours could be attributed to the effect of change in ambient light level. S2 investigated social interaction by comparing the occurrences of people visiting the squares alone, in pairs, or in groups of three or larger, in DL and in EL. The objective was to establish whether social interaction was sustained at the same time of day in EL after dark. Study 3 (S3), a survey, focused on the assessment of users’ environmental appraisals (interpretation and evaluation) of the two squares, by comparing the appraisals in DL and in EL after dark. Furthermore, it investigated the possible correlation between appraisals of perceived atmosphereand self-reported social interaction after dark. Finally, Study 4 (S4), a lighting intervention, focused on the environmental setting in Kirseberg Square, investigating the influence of spatial light characteristics on users’ environmental appraisals of this square after dark.The findings of the observational studies (S1 and S2) suggest that electric lighting can sustain spatiotemporal patterns of user behaviour, including movements, stationary activities, and social interaction in public squares after dark. It was found that the change in behaviour in terms of stationary activities and social interaction could be attributed to the effect of change in ambient light level between DL and EL. The results suggest that the facilitation of stationary activities and social interaction requires that special attention is dedicated to perceptual attributes of light, specifically the level of uniformity and contrasts in the visual field. The results of the survey (S3) show that users’ environmental appraisals of perceived lighting qualities, visual accessibility, reassurance and atmosphere were consistently assessed as higher in DL than in EL in both squares. Furthermore, the findings suggest that users’ self-reported social interaction is associated with the perceived atmosphere in EL after dark. The results of the lighting intervention (S4) in Kirseberg Square suggest that spatial light characteristics are an important consideration for the appreciation of space and for the enhancement of atmosphere in public squares after dark. It is proposed that a balance of luminance in the visual field is beneficial to the appreciation of space and atmosphere enhancement.The thesis concludes that social interaction in public squares after dark can be sustained with lighting, and emphasizes that lighting design criteria for public squares should extend beyond providing visual accessibility and reassurance to include the practice of attuning atmospheres. While appropriately designed lighting in public squares can sustain social interaction, lighting also entails negative consequences associated to energy use, light pollution and a negative impact on ecological systems. Future research on public spacesshould thus address the spatial distribution of light, also with regards to how energy consumption may be lowered, costs reduced and obtrusive light avoided. In addition, research to advance knowledge on the influence of spatial as well as spectral characteristics is advocated.