The age crime curve refers to the assumption that crimes are most prevalent during mid to late adolescence. That is, the incidence of crime increases with age until individuals reach about 16 to 20. The incidence of crime then decreases with age in adulthood.
According to Hirschi and Gottfredson (1983) this age crime curve is universal. That is, the curve seems to apply, at least roughly, in all demographic and socioeconomic categories as well as for all offences. Nevertheless, recent studies indicate the precise age at which crime peaks depends on a variety of characteristics and conditions as well as varies across offences (e.g., Fagan & Western, 2005).
Furthermore, some research has uncovered more than one peak. To illustrate, as Loeber, Menting, Lynam, Moffitt, Stouthamer-Loeber, Stallings, Farrington, and Pardini (2012) showed, when adolescents are impulsive but high in IQ, the incidence of crime peaks at late adolescence and then again during the late 20s.
In general, the prevalence of crime peaks during mid to late adolescence. Supposedly, during early adulthood, maturation of the brain or other changes in the role of individuals diminishes the incidence of crime.
Yet, as Fagan and Western (2005) observed, the assumption that crime peaks during mid to late adolescence is not always accurate and varies across categories of offences. To illustrate, for offences that relate to vehicles, such as culpable driving, or drug use, the incidence of crime is higher in early adulthood than in adolescence. For offences that relate to theft, the incidence of crime does not differ between early adulthood and adolescence. Finally, for offences that relate to vandalism and several other serious crimes, the incidence of crime is higher in adolescence than in early adulthood.
Likewise, socioeconomic status also affects the age of this peak. The peak is earlier in people from a lower socioeconomic status (Fagan & Western, 2005).
The relationship between crime and age is complex (Fagan & Western, 2005). For example, from the ages of about 6 to 10, the prevalence of physical aggression tends to increase. Yet, from the ages of about 10 to 13, the prevalence of physical aggression tends to decrease, as some people mature. Yet, in the subset of individuals who continue to perpetrate destructive behaviors, these acts become most severe at around 15 to 16 years of age, besides homicides, which tend to be committed later (for a review, see Loeber, Menting, Lynam, Moffitt, Stouthamer-Loeber, Stallings, Farrington, & Pardini, 2012).
After late adolescence, the prevalence of crime tends to diminish. Yet, the decline in theft tends to be more rapid than is the decline in violence (Loeber, Menting, Lynam, Moffitt, Stouthamer-Loeber, Stallings, Farrington, & Pardini, 2012).
One countervailing mechanism can obscure the usual tendency of crime to diminish with age. Specifically, although individuals may become less inclined to commit serious offences as they mature, the gravity of these acts is also correlates with the number of convictions--a figure that tends to increase with age. That is, as Liu, Francis, and Soothill (2011) showed, the effects of maturity and number of convictions, both of which are positively associated with age, may nullify each other, at least in a segment of the population.
Regrettably, according to Liu, Francis, and Soothill (2011), past research has conflated the effects of maturation and number of convictions. However, when number of convictions is controlled, the effect of maturation prevails, and age is inversely associated with the severity of crimes& that is, the gravity of offences diminishes around early adulthood. In contrast, when age is controlled, number of convictions is positively associated with the severity of crime.
The age crime curve, at first glance, might imply the likelihood and severity of crimes tends to diminish after individuals reach early adulthood. But this conclusion overlooks the observation that clusters of individuals show different trajectories.
To clarify, most people desist from crime after they reach 18 or so, called adolescence-limited anti-social behavior (Moffitt, 1993). But, some people continue to commit offences afterwards, called life-course persistent anti-social behavior (Moffitt, 1993). Indeed, their crime often escalates into more severe offences. In addition, Patterson, Reid, and Dishion (1992) differentiate between life-course persistent criminals who are early versus late starters (for additional clusters, such as intermittent offenders and slow uptake chronic offenders, see Bushway, Thomberry, & Krohn, 2003).
Even the trajectories of life-course persistent criminals differ markedly from each other. Some of these criminals primarily confine their offences to the same category, such as arson (Soothill, Francis, & Liu, 2008), called specialists. Some criminals engage in a range of crimes, called generalists (Soothill, Francis, & Liu, 2008). And some, but not all, of these generalists engage in increasingly more serious crimes over time, called escalation.
The Pittsburgh Youth Study--a longitudinal study of 1517 men, who were tracked from late childhood to their late 20s--differentiated three constellations of escalation (for a summary, see Loeber, Menting, Lynam, Moffitt, Stouthamer-Loeber, Stallings, Farrington, & Pardini, 2012). The first constellation, called the overt pathway, revolves around observable aggression. Minor aggression escalates into physical fighting and then serious violence.
The second constellation, called the covert pathway, revolves around unobservable offences. Often, before the age of 15, individuals begin with frequent lying or shoplifting that may escalate into property damage, such as vandalism or lighting fires, and later moderate delinquency, such as fraud or pick pocketing, sometimes culminating in theft and burglary.
The third constellation, called the authority conflict pathway, revolves more around disobedience. Even before the age of 12, these individuals tend to be stubborn before becoming overtly disobedient or defiant and eventually avoiding authority altogether, epitomized by truancy or running away from home (for evidence of similar patterns, see Tolan, Gorman-Smith, Loeber, 2000).
Many practitioners and scholars assume that lifelong criminals tend to exhibit an escalation in the severity of crimes. That is, according to these experts, if adolescents who engage in minor offences do not mature but continue to offend, they will tend to perpetrate more severe crimes in the future.
Although the evidence of this escalation in the severity of crime is patchy, some research does substantiate this possibility. Soothill, Francis, and Liu (2008), for example, showed that arson, blackmail, kidnapping, and threats may escalate into homicide. That is, relative to the general population, people who have committed these crimes are more likely to murder someone in the future. To illustrate, as reported by Soothill, Francis , Ackerley , and Fligelstone (2002), people who have committed acts of blackmail are, in the future, about five times more likely than a typical person to murder someone in the future. Furthermore, as Liu, Francis, and Soothill (2008) showed, men who have kidnapped someone are 30 times more likely than a typical male to commit an act of murder in the future.
Yet, escalation is not inevitable. Soothill, Francis, and Liu (2008) concede that individuals may switch between crimes, such as blackmail and kidnapping but not necessarily become involved in more serious offences over time.
A further controversy revolves around whether people who escalate into more severe offences still continue to perpetrate milder offences. Some research indicates these individuals maintain these milder offences as well (Farrington, 2003). In contrast, other research indicates these individuals disengage from these milder offences (Graham & Bowling, 1986;; Rutter, GiUer, & Hagell, 1998).
Many explanations have been proposed to explain the age crime curve. These explanations are primarily intended to clarify why the prevalence, and usually the severity, of crimes diminishes around early adulthood. For example, many scholars ascribe this decrease in crime around this age to changes in the neurobiology or the roles of individuals. Yet, other explanations have also been offered.
Researchers often assume that criminal behavior is often a response to feelings of strain, such as anxiety, in the aftermath stressful events. That is, when people experience strain, they often engage in impulsive and egocentric, rather than considered and cooperative, means to overcome these feelings.
Hoffmann (2013) invoked this perspective to explain why the prevalence or severity of crime might diminish as individuals reach adulthood. In particular, after their teenage years, individuals may be granted more responsibility and choice. This responsibility and choice affords these individuals with more opportunities to resolve stressful events. Consequently, as individuals age, stressful events are not as likely to evoke strain and crime.
To assess this possibility, Hoffmann (2013) conducted a study in which participants completed a measure that assesses the number of stressful life events they have experienced in the last 8 years, including divorces or death of family members. In addition, they completed measures that gauge the degree to which they experience negative emotions as well as various control variables, such as self-esteem and family cohesion. As predicted, if individuals had experienced many life events, they were more likely to have engaged in criminal or delinquent behavior. Yet, this relationship was not as pronounced in people who were older than 18 or so. These findings are consistent with the notion that older individuals can withstand stressful events more effectively.
Unsurprisingly, if individuals are more impulsive rather than considered or cautious, the likelihood of offences is especially likely to escalate during adolescence, but then flatten or decrease at the beginning of adulthood, before sometimes increasing slightly during the late 20s (Loeber, Menting, Lynam, Moffitt, Stouthamer-Loeber, Stallings, Farrington, & Pardini, 2012). However, if these individuals also exhibit a low IQ, impulsivity is not associated with this escalation or deceleration of crime.
This pattern of findings was observed in the Pittsburgh Youth Study--a longitudinal study of 1517 men, who were tracked from late childhood to their late 20s. In this study, to gauge impulsivity, three cognitive measures were administered to participants, while they were young (for more discussion about impulsivity and related measures, see impulsivity).
The first measure was the trail making test. For this test, a set of letters and numbers appear on a sheet. Participants must draw a trail from A to 1 to B to 2 and so forth and, therefore switch between letters and numbers. A slow time reflects impairments in cognitive control. The second measure was the Strop test in which a series of words, presented in various colors, is presented. Participants need to specify the color rather than read the word. Again slow times reflect impairments in cognitive control. The final measure was a time perception task in which individuals need to estimate various time intervals. Accuracy is related to performance on the other two tasks. Finally, the WISC was administered to assess intelligence.
The reason that impulsivity affects crime rate more in people with a high IQ is not clear. Perhaps, when IQ is high, individuals expect to achieve more in school and so forth. Limited achievement, as a consequence of impulsivity, may be especially upsetting to these individuals.
In general, as Loeber, Menting, Lynam, Moffitt, Stouthamer-Loeber, Stallings, Farrington, and Pardini (2012) showed, the causes of violence are similar to the causes of theft, such as inadequate achievement at school. However, as the individuals aged, the causes of violence seemed to differ from the causes of theft. Exposure to guns and family reliance on welfare were key predictors of violence. In contrast, child maltreatment and ethnicity were more likely causes of theft.
To ascertain whether the severity of crimes differ across age, researchers need to utilize an index that reflects the gravity of offences. In their review of the literature, Liu, Francis, and Soothill (2011) differentiate four broad approaches to generate these indices. Specifically, researchers can:
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Last Update: 7/20/2016