Citation

Whitley E, Batty GD, Gale CR, Deary IJ, Tynelius P, Rasmussen F. Psychosom. Med. 2010; 72(4): 390-396.

Affiliation

MRC Social and Public Health Sciences Unit (E.W., G.D.B.), University of Glasgow, Glasgow, UK; Centre for Cognitive Ageing and Cognitive Epidemiology (G.D.B., I.J.D.), Department of Psychology, University of Edinburgh, Edinburgh, UK; The George Institute for International Health (G.D.B.), University of Sydney, Sydney, Australia; MRC Epidemiology Resource Centre (C.R.G.), University of Southampton, Southampton, UK; and Department of Public Health Sciences (P.T., F.R.), Karolinska Institute, Stockholm, Sweden.

Copyright

(Copyright © 2010, American Psychosomatic Society, Publisher Lippincott Williams and Wilkins)

DOI

10.1097/PSY.0b013e3181d137e9

PMID

20190131

Abstract

Objective: To examine the association between low intelligence (IQ) and increased risk of assault. Previous studies have been relatively small, have not adjust for socioeconomic status, and have not examined method-specific assaults. Methods: Cox proportional hazards regression was used to explore IQ associations with assault by any means and by four specific methods in a large prospective cohort of 1,120,988 Swedish men. Study members had IQ measured in early adulthood and were well characterized for socioeconomic status in childhood and adulthood. Men were followed-up for an average of 24 years, and hospital admissions for injury due to assault were recorded. Results: A total of 16,512 (1.5%) men had at least one hospital admission for injury due to assault by any means during follow-up. The most common assault was during a fight (n = 13,144), followed by stabbing (n = 1,211), blunt instrument (b = 352), and firearms assaults (n = 51). After adjusting for confounding variables, lower IQ scores were associated with an elevated risk of hospitalization for assaults by any means (hazard ratio per standard deviation decrease in IQ, 1.51; 95% confidence interval, 1.49, 1.54) and for each of the cause-specific assaults: fight: 1.48 (1.45, 1.51); stabbing: 1.68 (1.58, 1.79); blunt instrument: 1.65 (1.47, 1.85); and firearms: 1.34 (1.00, 1.80). These gradients were stepwise across the full IQ range. Conclusions: Low IQ scores in early adulthood were associated with a subsequently increased risk of assault. A greater understanding of mechanisms underlying these associations may provide opportunities and strategies for prevention.

Language: en