"The greater the gap between rich and poor, the more likely people will grow up a drug user, a criminal, less educated, obese, pregnant while a teenager, even less trusting of others."The New Zealand poor comprise non-wealthy welfare recipients and non-wealthy workers. The problems that are attributed to wealth inequality are more prevalent among beneficiaries than among the working poor. That is amply illustrated by the difference in the incidence of these problems (bar obesity which has its roots in traditional diet/lifestyle change) between Maori and Pacific people. Teenage pregnancies, criminality, and substance abuse are more prevalent among Maori. Maori are far more likely to be on benefits than Pacific people.
What is even more striking is that Asians are the least wealthy group yet, thus far, do not under-achieve, abuse drugs or offend in disproportionate rates. Their various cultures are not beset with social problems. I don't suppose any academic raised these flies in the ointment.
The two things that work against the problems identified are strong families and work. Both are eroded by unconditional welfare. Not by income inequality.