I was finally able to open the link....I couldn't when I first tried.
"There were 6872 participants aged ⩾16 years included in this study. The prevalence of violence perpetration decreased linearly with increasing IQ [16.3% (IQ 70–79) v. 2.9% (IQ 120–129)]. After adjusting for demographic and behavioral factors, childhood adversity, and psychiatric morbidity, compared with those with IQ 120–129, IQ scores of 110–119, 100–109, 90–99, 80–89, and 70–79 were associated with 1.07 [95% confidence interval (CI) 0.63–1.84], 1.90 (95% CI 1.12–3.22), 1.80 (95% CI 1.05–3.13), 2.36 (95% CI 1.32–4.22), and 2.25 (95% CI 1.26–4.01) times higher odds for violence perpetration, respectively."
But I stand by my previous post about under-educated people. I still think poverty, mental health, and lack of services has more to do with violence than IQ.