How can upbringing in a disrupted family explain criminal behaviour?

The longitudinal study began in 1961 and 411 south-London males aged 8-9 years participated, all where white working class and came from 6 state primary schools. The researchers conducted psychometric tests such as IQ, attainment, personality and psychomotor impulsivity. The boys were also interviewed between the ages of 8 -48 , they were questioned on living circumstances, employment and drinking and drugs. Other people interviewed include the mother/fathers, friends and teachers. In addition to both the qualitative and quantitative data collected, secondary data was collected in the form of criminal records.  

Results found that delinquency rates were higher among the 75 boys at age 15 who came from permanently disrupted homes than boys from intact families.  However they also found similar rates between disrupted families and intact high conflict families (families which were high in tension and/or had disagreement between parents).  Furthermore boys who had lost their mothers were more delinquent than boys who had lost their fathers. Overall a significant finding was that the most important childhood ( 8-10 yrs) risk factors  for later offending measures were of family criminality, daring personality, low school attainment, poverty and poor parenting.

In conclusion Juby and Farrington conclude that some kinds of disrupted families (where the boy doesn’t remain with the mother) are criminogenic and will produce children more likely to commit delinquency. However, they also state that some kinds of intact families ( those with high conflict ) are just as criminogenic and can lead to intergenerational transmission of offending. Thus, they state it is not the disruption itself which leads to delinquency but rather the pattern of pre- and post- disruption events that can result in high levels of delinquency.