Among possible biological factors, there have been
studies on injuries and complications associated with
pregnancy and delivery, because of the suggestion
that these might produce neurological damage,
which in turn could lead to violence. In a study in
Copenhagen, Denmark, Kandel & Mednick (67)
followed up over 200 children born during 1959–
1961. Their research showed that complications
during delivery were a predictor for arrests for
violence up to the age of 22 years. Eighty per cent of
youths arrested for committing violent offences
scored in the high range for delivery complications
at birth, compared with 30% of those arrested for
committing property-related offences and 47% of
youths with no criminal record. Pregnancy complications,
on the other hand, did not significantly
predict violence.