Remember the Marshmallow experiment? That's the one to see how long a child could hold out against the temptation to eat a marshmallow, correlated with an enhanced ability at delayed gratification and later adult success. A new study looks at children with different behaviors, oppositional and antisocial. How did they fare?
Conduct problems “that violate the rights of others and conflict with societal norms” are estimated to impact nearly 6% of children and adolescents globally, making it a typical “mental health difficulty.” In children, these conduct problems are often due to early maltreatment, neurologic alterations, and what is termed a criminogenic environment. In adolescents, conduct problems are often due to a dissonance between how mature the adolescent feels and the legal and social constraints they experience. Adolescents seem to age out of their conduct problems, children not so much.
The study combined two longitudinal studies
- Fast Track – looked at 754 kindergarten children in 55 high-risk schools nationally, based on crime and poverty rates of the school communities. These children were in the control arm of a study looking at intervention in these high-risk students.
- Child Development Project – another national cohort of 585 kindergarten children investigating their social development.
Conduct problems assessed in kindergarten were based on parent and teacher-reported issues. The outcomes were the costs of criminal conduct defined as costs to both the criminal and the victim. They included a measure of lost productivity beyond the direct legal and health-related expenses.  Criminal costs came from administrative court data; health costs were based on self-reported Medicaid or other health services use. Government services, such as Supplemental Income/Disability/Social Security, Aid to families with dependent children, and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) were also self-reported.
- Violent criminal and criminal + victim costs represented the most significant costs in adolescence and adulthood.
- Costs to the legal system were by far the largest. Government services are a small fraction of the overall costs, roughly 0.6%, and medical costs were 13%
- Total costs across all categories for the male sample equated to $182,904; for the female sample, it equated to $98,634.
- The individuals in the top 5% of behavior problems  were responsible for most of the expenditures, which held for men and women.
- More importantly, the costs were far more significant in those identified as high-risk in kindergarten. A subgroup of individuals diagnosed in adolescence with “oppositional defiant disorder in 6th or 9th grade” generated costs 84% less than those identified in kindergarten during adolescence and 95% less during adulthood. The behavioral disorders developing in adolescence do age out.
“Left untreated, conduct problems confer risk for elevated mental and physical health problems, greater public services utilization, as well as increased likelihood of participation in violent and criminal behavior throughout the lifespan.”
Like the successful children of the marshmallow experiment, early behaviors, in this case, described as problems rather than advantages, can have lasting impacts. While monetizing costs can be uncertain, the data suggest a correlation between early childhood traits and later adult behavior. The bottom line is that not all behavior is “childhood-limited.” It would be helpful to identify and help those individuals in their most formative years.
 Criminal costs are overall expenses to the legal system; criminal + victim costs include the lost productivity of both offender and victim and their other costs. Criminal + victim may be a better measure of overall societal costs.
 Study results were presented as increasing standard deviations. I have expressed that using the Empirical Rule for normal distributions placing a one standard deviation at the top 5%.
Source: Kindergarten conduct problems are associated with monetized outcomes in adolescence and adulthood Journal of Child Psychology and Psychiatry DOI:10.1111/jcpp.13837