"Much more strongly" is an overstatement, and this thesis doesn't take into account the multiplicative (not linear) effects of discrimination - in all its institutional and informal forms - and poverty. Crime in Japan tracks more closely with Buraku heritage than with income, and they are genetically indistinguishable from the rest of the population. This is a social problem with a social solution, that racist mid-century urban planners and policymakers made phenomenally worse by encouraging white flight.