The role of urban green space in promoting health and well-being is related to nature connectedness and biodiversity: Evidence from a two-factor mixed-design experiment

•Greenspace is better than gray space at helping high-NC people recover from tasks.•Biodiversity triggers better eudaimonic experience in high-NC individuals.•Low-NC individuals are less sensitive to the disparity of environments.•Low-NC may be more adapted to gray space. The health and well-being benefits of green space over gray space have been widely recognized. However, the congruence effect implies that the outcome of environmental exposure is influenced by one's psychological relationship with the environment. This study conducted a two-factor mixed-design experiment with college students (n = 68) to investigate the moderating effect of the psychological factor of nature connectedness (NC) on the short-term benefits of exposure to one urban gray space and two low- and high-biodiversity urban green spaces after completing demanding tasks. Environmental exposure was simulated through 10-minute audio–video clips in a laboratory setting. The findings suggest that low-NC individuals adapt to gray space because they reported neutral to positive results in emotional valence and eudaimonic experience. Additionally, they actively engaged with environmental information for a longer duration, as indicated by the frequency of skin conductance responses. Consequently, they lack the urgency to escape from gray space although they benefit more from green space. Conversely, high-NC individuals tend to seek out green space as a “shelter” in urban areas, because they are vulnerable to gray space with ambient noise and experience significantly better eudaimonic outcomes in the high-biodiversity green space. Our results elucidate the previously found relationship between NC and green space visitation, while also emphasizing the need to comprehend the role of urban green space and the value of biodiversity from an NC perspective.