The authors of this study integrate recent data with data on ancestral ethnic groups' exposure to the slave trade in order to examine the relationship between this historical exposure and children vaccination status against measles. They find evidence to support their hypothesis that children from mothers whose ancestors belonged to an ethnic group that exported slaves are less likely to be vaccinated against measles, theorizing that this correlation stems from distrust in medical and governmental institutions. Supporting this theory, they also find that groups historically exposed to the slave trade that have higher preference for traditional practices are even less likely to vaccinate their children against measles.