This chapter expands on an earlier article (Folland and Iversen, 2014), bringing into view the many studies since then. These include the relationship of social capital to one’s age, ethnicity, gender, education and other categories described in recent findings. Of particular note, the authors sort out the complexity of the studies on income inequality and its effect on social capital. One study finds no relation between inequality and trust; yet another finds a negative correlation between social capital and inequality. In one study of kindergarten children it was found that the young girls were more trusting than the boys.