A recent Duke investigation suggests that a small portion of the general population could be responsible for a majority of costly social services.
The investigators based their findings on data compiled from following a group of 1,037 New Zealanders for almost 40 years, historically referred to as the Dunedin Study. According to the Duke study's findings, 81 percent of criminal convictions, 78 percent of pharmaceutical prescription fills and 77 percent of fatherless child-rearing cases among the Dunedin group could be attributed to a a fifth of all study participants. Looking back at the data, the research team found that this “high-need/high-cost” group of adults had compromised brain heath, manifesting in tests as early as age three.
“It’s surprising that the same group of individuals show up in in service sectors again and again and that these high-need/high-cost individuals can be predicted from age three with over 85 percent accuracy,” wrote Terrie Moffitt, Nannerl O. Keohane University professor and study co-author, in an email.
This idea of high-need/high-cost individuals was consistent with the “Pareto principle,” she explained, which suggests that 80 percent of any given system's resources are typically allocated to just 20 percent of that system’s users. To determine whether the Dunedin participants exemplified this idea, the team analyzed data from their social welfare, disability insurance, medical records and criminal court records.
Moffitt noted that children who would eventually comprise the costly 20 percent of adults could be predicted through a pediatric neurological examination that tested for verbal comprehension, language development, motor skills and social behavior. According to the study, the Dunedin children who tested with low scores on the brain health index were much more likely to be associated with elevated social costs as adults.
The team found that poverty was not the only reason children with lower test scores ended up as high-cost adults. Moffitt explained that children born into middle class families were also among the fifth of the population that the study found to be high-cost.
"To test whether the predictive findings were all down to poverty, we limited our cohort of research participants to only those who grew up in middle class homes," she wrote. "We re-ran all the predictive models, and the findings remained the same. So although it is true that many infants with problematic brain health come from poor families, even in middle-class families a preschooler's brain health strongly predicted their rate of use of public services during adulthood."
The study authors noted that although these findings could be used "for stigmatizing and stereotyping," a more productive solution would be to support disadvantaged children early on, leading to a lower burden for taxpayers down the road.
Before her team's findings, Moffitt wrote, researchers had underestimated the degree to which childhood risk factors could predict adult outcomes.
Moffitt added that this specific analysis of the Dunedin Study was inspired by questions from policy-makers on whether effective preschool programs are linked to positive adult outcomes. Now that a link has been established, she explained, lawmakers may begin to consider effective preschool programs as “good returns on investment,” potentially paving the way for publicly funded preschools.
Moffitt noted that one of the main reasons her team was able to establish such a strong link was due to the setup and design of the study.
“The data from New Zealand provided a unique opportunity because the nation’s records gave us access to both register data and longitudinal cohort studies,” Moffitt wrote. “Scandinavian countries have national registers, but no longitudinal cohort studies, and the United States has neither longitudinal cohorts nor national registers.”
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