Scholars and laypeople alike debate what causes young people to commit crimes. Although most states mark the legal transition from adolescence to adulthood at age 18, researchers question whether the human brain is fully mature at that age. As part of the NIJ Study Group on the Transition from Juvenile Delinquency to Adult Crime, several scholars examined the differences between juveniles who persist in offending and those who do not, and also looked at early adult-onset offending.
On this page find:
- The Age-Crime Curve
- Persistence, Desistance and Onset
- Special Categories of Offenders
- Preventive Actions for Known Delinquents
- Financial Benefits and Costs of Interventions
- Research and Policy Recommendations
- Study Group Reports
The Age-Crime Curve
The prevalence of offending tends to increase from late childhood, peak in the teenage years (from 15 to 19) and then decline in the early 20s. This bell-shaped age trend, called the age-crime curve, is universal in Western populations (see Figure 1).[1]
However, specific versions of the curve vary in significant ways. The curve for violence tends to peak later than that for property crimes.[2] Girls peak earlier than boys.[3] The curve is higher and wider for young males (especially minorities) growing up in the most disadvantaged neighborhoods.[4]
Source: Loeber, Rolf, and Rebecca Stallings, “Modeling the Impact of Interventions on Local Indicators of Offending, Victimization, and Incarceration,” in Young Homicide Offenders and Victims: Risk Factors, Prediction, and Prevention from Childhood, eds. Rolf Loeber and David P. Farrington, New York: Springer, 2011: 137-152. (View larger image.)
Persistence, Desistance and Onset
Continuity of offending from the juvenile into the adult years is higher for people who start offending at an early age, chronic delinquents, and young people who commit violent offenses. The Pittsburgh Youth Study found that 52 to 57 percent of justice-involved youth continue to offend up to age 25. This number dropped by two-thirds — to 16 to 19 percent — in the next five years.[5] However, there are large individual differences at play. Juveniles who start offending before age 12 are more likely to continue offending into early adulthood.[6]
Not all offense types have the same persistence. One study showed that drug dealing and possession of weapons had the highest likelihood of duration and persistence into early adulthood, while gang membership had a shorter duration. Marijuana use had the longest duration, two to four times longer than theft and violence.[7]
The median age of termination of offending was highest for drug trafficking (age 21.6). Minor offenses such as shoplifting and vandalism usually stop before age 18.[8]
The annual frequency of offending is higher for nonviolent crimes than for violence. The frequency usually peaks around ages 17-19 and remains stable over time only for a small number of individuals.[9]
Studies agree that 40 to 60 percent of justice-involved youth stop offending by early adulthood. For those who do persist, the transition from adolescence to adulthood is a period of increasing severity of offenses and an increase in lethal violence.[10] Most of the violence is directed at victims of the same age, and the age period of 16-24 is a high-risk time for violent victimization.[11] Many young people who offend at ages 18-20, which brings them into the adult justice system, would have been likely to desist naturally in the next few years.[12] Justice system processing may make them worse, rather than better. Somewhere between 10 percent and 30 percent of individuals start offending during early adulthood.[13]
Developmental studies of late adolescence and early adulthood do not support the notion that there is any naturally occurring break in the prevalence of offending at age 18.
Special Categories of Offenders
The average age of onset is earliest for gang membership (average age of 15.9), followed by marijuana use (16.5), drug dealing (17.0), gun carrying (17.3) and hard drug use (17.5).[14] Although drug dealing is rare, drug use is widespread among these individuals. Criminals report higher rates of substance use, and substance users report higher rates of offending compared with nonusers.[15] Of all offenses, dealing drugs and illegally carrying guns have the highest persistence from adolescence into adulthood.
Joining a gang increases the rate of offending, but gang involvement is often transient. One study found that most youths who join gangs do so at very early ages, typically between 11 and 15; ages 14-16 are the peak for gang involvement.[16] In contrast, most homicides are single events committed in the 19-24 age range. However, gang killings take place mostly during adolescence.
The studies looked at risk and protective factors. There is strong evidence that, for males, getting married and holding a stable job foster desistance from offending and that unstructured activities with peers are associated with persistence.[17]
The sparse research on adult-onset offending provides little information about why some people who were not delinquent during adolescence become adults who commit offenses. However, there is evidence that some factors inhibit offending during adolescence but not during adulthood. One study found that characteristics such as nervousness, anxiousness, social isolation and social inhibition were associated with adult-onset offending.[18]
Preventive Actions for Known Delinquents
There is good evidence that early interventions in childhood, such as home visits by nurses, preschool intellectual enrichment programs and parent management training, are effective in preventing delinquency. For example, an evaluation of the Elmira (N.Y.) Nurse-Family Partnership program found that at age 15, children of the higher-risk mothers who received home visits had significantly fewer arrests than controls. Another follow-up when the children were 19 showed that the daughters (but not the sons) of mothers who received home visits had significantly fewer arrests and convictions.[19]
Programs that target individuals can reduce offending in the early adult years. For example, the Seattle Social Development Project combined parent training, teacher training and skills training for children beginning at age 6.[20] At age 27, the intervention group scored significantly better on educational and economic attainment, mental health, and sexual health, but not on substance abuse or offending.[21]
Some interventions with older justice-involved youth (ages 14-17) have been successful. One long-term follow-up found that Multisystemic Therapy (MST) participants had lower recidivism rates (50 percent versus 81 percent), including lower rates of rearrest for violent offenses (14 percent compared with 30 percent). MST participants also spent 57 percent fewer days confined in adult detention facilities.[22]
Financial Benefits and Costs of Interventions
The financial benefits of intervention programs often outweigh the costs. One review found that this was true of multidimensional treatment foster care (MTFC) ($8 saved per $1 expended), functional family therapy ($10 saved per $1 expended), MST ($3 saved per $1 expended), vocational education in prison ($12 saved per $1 expended), cognitive-behavioral therapy in prison ($22 saved per $1 expended), drug treatment in prison ($6 saved per $1 expended) and employment training in the community ($12 saved per $1 expended).[23]
Research and Policy Recommendations
The Study Group concluded that there are significant gaps in knowledge about the development of offending careers between ages 15 and 29. Researchers know surprisingly little about how many juveniles persist into adult offending and what factors predict persistence. More needs to be known about factors that may influence offending between ages 15 and 29.
The researchers concluded that young adults ages 18-24 are more similar to juveniles than to adults with respect to their offending, maturation and life circumstances.
Changes in legislation to deal with large numbers of juvenile becoming adult criminals should be considered. One possibility is to raise the minimum age for referral to the adult court to 21 or 24, so that fewer individuals would be dealt with in the adult system.
Alternatively, special courts for young persons ages 18-24 could be established on an experimental basis, building on the experience of the United Kingdom. Several European countries, including Sweden, Germany and Austria, have long had separate young adult sentencing options and separate institutions for individuals ages 18-21. Special facilities for young adults already exist in some states, such as Pennsylvania.
Beyond that, there could be an “immaturity discount” for young adults that would involve a decrease in the severity of penalties, taking into account a young person’s lower maturity and culpability.
Study Group Reports
Bulletin 1: From Juvenile Delinquency to Young Adult Offending (Study Group on the Transition from Juvenile Delinquency to Adult Crime). Final technical report by Rolf Loeber, David P. Farrington and David Petechuk. NCJ 242931.
Bulletin 2: Criminal Career Patterns (Study Group on the Transition from Juvenile Delinquency to Adult Crime). Final technical report by Alex R. Piquero, J. David Hawkins, Lila Kazemian and David Petechuk. NCJ 242932. Read a summary of this report: Criminal Career Patterns (pdf, 2 pages)
Bulletin 3: Explanations for Offending (Study Group on the Transition from Juvenile Delinquency to Adult Crime). Final technical report by Terence P. Thornberry, Peggy C. Giordano, Christopher Uggen, Mauri Matsuda, Ann S. Masten, Erik Bulten, Andrea G. Donker and David Petechuk. NCJ 242933.
Bulletin 4: Prediction and Risk/Needs Assessment (Study Group on the Transition from Juvenile Delinquency to Adult Crime). Final technical report by Robert D. Hoge, Gina Vincent and Laura Guy. NCJ 242934. Read a summary of this report: Prediction and Risk/Needs Assessment (pdf, 2 pages)
Bulletin 5: Young Offenders and an Effective Response in the Juvenile and Adult Justice Systems: What Happens, What Should Happen, and What We Need to Know (Study Group on the Transition from Juvenile Delinquency to Adult Crime)Final technical report by James C. Howell, Barry C. Feld, Daniel P. Mears, David P. Farrington, Rolf Loeber and David Petechuk. NCJ 242935. Read a summary of this report: Young Offenders: What Happens and What Should Happen (pdf, 3 pages).
Bulletin 6: Changing Lives: Prevention and Intervention to Reduce Serious Offending (Study Group on the Transition from Juvenile Delinquency to Adult Crime). Final technical report by Brandon C. Welsh, Mark W. Lipsey, Frederick P. Rivara, J. David Hawkins, Steve Aos, Meghan E. Peel and David Petechuk. NCJ 242936. Read a summary of this report: Changing Lives: Prevention and Intervention to Reduce Serious Offending (pdf, 8 pages).