UC Riverside

The primary purpose of this dissertation was to examine geographic differences in leisure time activity engagement, geographic differences in social capital and it’s facets such as social support and the associations between social capital and physical health, and geographic differences in the relationship between activity engagement and cognitive performance (measured as IQ), as mediated by social capital. All studies in this dissertation utilized data from the ongoing Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging (i.e. CATSLife) which combines two longitudinal studies of twins and adoptees to explore individual differences in behavioral development and cognitive aging. By leveraging the twin-sibling structure of the CATSLife data, we were able to evaluate potential selectivity of geospatial, behavioral, and cognitive performance associations.

Study 1 used distal measures of rurality (IRRcounty) as well as proximal measures of rurality (IRRtract) to evaluate geographic differences in activity engagement. Results suggest that for some activity domains the distal measure of rurality was more informative (social activity engagement) whereas for some activity domains (sedentary) the proximal level of rurality was more informative. Interestingly, there were significant associations between both the distal and proximal measures of rurality for family activity engagement, but the distal measure was most informative.

Study 2 similarly evaluated geographic differences in distal measures of social capital (i.e. county level social capita index) as well as proximal measures of social capital through individual level facets of social capital (i.e. perceived support, number of close friends) to evaluate how these social measures influence physical health. Study 2 found few geographic differences in the proximal measures of social capital. the distal measure of rurality (IRRcounty) revealed that the more rural the county, the fewer number of close friends’ participants reported. Study 2 observed no geographic differences for any of the health measures (number of illnesses, somatic complaints, self-rated health).

Study 3 first examined geographic differences in cognitive performance (measured as IQ) and revealed that once accounting for sibling similarities, no geographic differences in IQ were observed. Next study three evaluated the relationship between activity engagement and cognitive performance as mediated by social capital. Social capital alone was not shown to be a mediating factor between activity engagement and cognitive performance. However, when including the interaction term between social capital and rurality, models suggested that social capital plays an important role in moderating the relationship between cognitive activity engagement or engaging in hobbies that were rated to be cognitively demanding on Full Scale IQ for individuals who reside in urban areas more than for individuals who reside in rural areas.

Collectively these studies highlight the interplay between the environment and the individual and the implications of this interaction for human development. What is more, these studies demonstrate the geographic differences in leisure time activity engagement, informing the literature on the implications for examining activity engagement from proximal and distal levels of the environment. Additionally, these studies address gaps in the literature and illuminate the relationships between social capital, activity engagement and cognitive performance.