Eis um estudo para uma sociedade homogênea (como raças não existem, deveríamos usar outro termo para o título do artigo…ou jogá-lo fora):

Using prefecture level data of Japan for the years 1979 and 1996, I explore the extent to which inequality, age heterogeneity, and social capital have an effect upon interpersonal trust. The major finding is that inequality is associated with low trust, while generational heterogeneity is associated with high trust. However, this tendency is not observed when the sample includes female respondents only. These results are not changed when I instrument for inequality using the relative size of the mature-aged cohort.