Pertinent quote from the results section of the publication:
Most people who come from a socio-economically less favorable background do not commit more crime than people who come from a more favorable background, and it also happens that people from a more favorable background do commit crime. This means that even if there is a connection between socio-economic background and involvement in crime, that connection is weak. It is not possible to appreciably predict who will commit crimes based on knowledge of people's socio-economic background.
https://bra.se/publikationer/arkiv/publikationer/2023-03-01-socioekonomisk-bakgrund-och-brott.html
yup it's combination of low iq and low impulse control. there are plenty of low iq people in India and Asia, they also commit more crimes than the average, but not at the level of blacks