Under such circumstances, it may have been evolutionarily useful to take very high risks and use violent aggression in order to try to increase status and reproductive success rather than become genetically extinct. This may explain why males have higher crime rates than females and why low status and being unmarried is associated with criminality. It may also explain why the degree of income inequality of a society is a better predictor than the absolute income level of the society for male-male homicides; income inequality creates social disparity, while differing average income levels may not do so.