April 9, 2015

expert reaction to paper on heritability of sexual offending in men

A paper published in the International Journal of Epidemiology has examined the relative contribution of environmental and genetic factors on sexual crime, reporting that genes may account for familial clustering of sexual offending, rather than shared environment.

Prof. Gil McVean, Professor of Statistical Genetics, University of Oxford, said:

“The data show clear differences in relative risk of recurrent sexual crime among people with different types and levels of relatedness (father, full-brother, maternal half-brother, paternal half-brother). However, turning these numbers into estimates of heritability makes some strong – and possibly unmet – assumptions, the key one being that the environment is fully shared by maternal half-brothers and full brothers and fully unshared between paternal half-brothers. For example, the contribution of the father to ‘shared environment’ is likely to differ between full brothers and maternal half-brothers, which might explain why the authors estimated such a low contribution of shared environmental risk (2% – compared to 40% for genetics). ”

‘Sexual offending runs in families: A 37 year nationwide study’ by Långström et al. published in International Journal of Epidemiology on Thursday 9th April. 

Declared interests

Prof. Gil McVean: I am co-founder of Genomics PLC, which develops tools and applications in high throughput genome analytics.