Criminal behavior and age: a test of three provocative hypothesis.

• Author: Tittle, Charles R.

1. INTRODUCTION

   Issues about age and crime are among the most important in criminology. This is due largely to Hirschi and Gottfredson,(1) who contend that the familiar inverted J-curve association between age and crime is invariant, inexplicable with social science variables, and involves no interaction between age and any variable that explains or correlates with crime.

   These three hypotheses bear on several trends and issues. First, they challenge the criminal careers perspective that life cycle patterns of offending take many forms, each requiring specific explanations and longitudinal research for testing.(2) If all people, including frequent offenders, commit more crime in the late teen years than later, then career offending is different only in amount, and the necessity of explaining different trajectories with special theories is vitiated. Moreover, if the causes of crime are the same at all ages, the call for longitudinal research inherent in the career criminal perspective is irrelevant.(3)

   Second, the Hirschi-Gottfredson position casts doubt on developmental perspectives that portray the determinants of crime as age-graded and variable over the life course.(4) If the causes of crime do not interact with age and the age-crime relationship is inherent, invariant, and inexplicable, then criminologists need only identify the general causes of crime and apply them to explain constant differences among individuals and categories in likelihood of criminal behavior, without reference to age patterned increases and decreases in the probability and volume of criminal behavior.

   Third, these hypotheses challenge practices of organizing criminological work around age differentiations such as juvenile, adult, and aged, or alternatively, of seeking age comprehensive samples in testing theories about crime.(5) If the causes of crime are the same at all ages, and if age patterns are inexplicable, then dividing labor to study crime within specific age categories and seeking age-comprehensive samples for research makes no sense.

   Finally, if age and crime are related in constant ways across all conditions, and inexplicable except by the biology of aging itself,(6) then the adequacy of numerous general social theories that imply an ability to account for age variations is in doubt and the import of social, relative to biological, influences is potentially diminished.

2. THE EVIDENCE

   1. INVARIANCE

      Evidence concerning "invariance" is difficult to judge because Hirschi and Gottfredson were not entirely clear about their definition. Three types of invariance have been investigated--parametric, mathematical form, and individualistic. Parametric concerns details of the relationship between population characteristics and crime rates, including means, standard deviations, and skewness of the distribution, as well as ages of onset and peaks for different crimes and populations.(7) Steffensmeier et al.,(8) Greenberg,(9) and others(10) have reported such work. Results show that the relationship between age and crime is not exactly the same in all details for all crimes and all populations. Thus, if Hirschi and Gottfredson meant to assert parametric invariance, they are clearly wrong. However, it is doubtful they meant such particularism, since they acknowledge variation in details, emphasizing their concern with a "remarkably robust age effect" and not with "statistical noise" indicating "trivial variations"(11) or with "an occasional factoid apparently contrary to the thesis."(12)

      A second type of invariance, and the one that Hirschi and Gottfredson seem to propose, concerns the shape of the curve describing the relationship between age and crime in any population. The evidence they review,(13) as well as subsequent research,(14) and even the data examined by Steffensmeier and his associates,(15) is consistent with the contention that relationships between age and many kinds of crime for various populations follow a similar pattern characterized by a single peak occurring fairly early in the life cycle (usually in the late teens for most offenses) with steady declines thereafter.

      Individualistic invariance concerns differences among categories of individuals in trajectories of prevalence and incidence of crime over the life cycle. Much research based on criminal careers and developmental paradigms shows categorical deviations from modal patterns, as well as differences among categories of people in starting ages, rates of offending at various ages, age at which cessation occurs, and different trajectories of offending.(16)

      Thus, the empirical standing of the invariance hypothesis depends partly on Hirschi and Gottfredson's definition. If invariance is similarity in the shape of the curves representing the relationship between age and various kinds of crime for different populations, current evidence is consistent with the hypothesis. But, if invariance means that the particular details of the relationships between age and crime for all offenses, social groups, points in history, and for all aspects of offending are similar, then the evidence contradicts it. We believe that the argument pertains to the shape, or form, of the age-crime relationship for various populations.

      However, even though research results have supported this kind of invariance, it has not been unambiguously established because most studies use official data, which may be differentially valid for various age groups and crimes. Self-reports can potentially overcome this weakness by tapping criminal behavior regardless of whether the offender is apprehended by the police or observed by a victim. But only a few such studies include randomly selected respondents across a wide age range.(17)

   2. INEXPLICABILITY

      Whether relationships between age and various kinds of criminal behavior, whatever their form, can be explained with social scientific variables remains an open question. Few attempts to explain empirically the associations between age and crime, particularly based on a wide range of ages, have been undertaken, and data used in those few instances have not included enough key variables to permit strong conclusions. Some studies have partially succeeded in accounting for age-crime relationships,(18) but no attempt has been fully satisfactory.(19) This may be because many potential explanations for the age-crime relationships have not been tested.(20)

      Indeed, Gottfredson and Hirschi propose a theory that could account for age-crime relationships, despite contending that such relationships cannot be explained.(21) Their theory says that crime results from the interaction of low self-control and opportunity. Given the opportunity, those with low self-control commit crime without considering long range consequences because it gratifies their immediate needs. Low self-control, said to be largely, though not entirely, fixed in early childhood,(22) presumably permits natural motivations toward crime to be expressed in actual criminal behavior throughout life, thereby explaining differences among individuals in criminal behavior at all ages. However, Gottfredson and Hirschi contend that differences in self-control cannot explain age-crime associations because everyone experiences an age effect. Variations in criminal behavior between those with different degrees of self-control at any age will be similar to such differences at any other age even though the absolute amount of crime by everybody changes over the life cycle in conformity with the inverted-J curve.

      Yet, levels of self-control may not be fixed early in life as Gottfredson and Hirschi suggest. Their own arguments seem to imply that low self-control may change with experience. Crime is said to be attractive because it pays in the short run, but it is committed mainly by those with weak self-control because they do not contemplate the inevitable long term consequences. Over time, however, as the costly consequences of criminal behavior unfold, those who begin with low self-control may gradually learn to defer gratification. Thus with age, many people may increase their self-control.

      Some improvement in self-control with maturation is acknowledged by Gottfredson and Hirschi(23) and the possibility of large change is consistent with the image of rationality among humans that they endorse. Experiential learning can occur without external socialization and without changes in major life course events. If self-control increases with age and low self-control largely accounts for criminal behavior, then at some point in the age cycle crime will begin to go down, producing the single peaked, inverted J-curve distribution of crime by age.(24) And this process could occur without influence of any of the variables that Gottfredson and Hirschi have rejected as causes of crime.

      Further, even if self-control is constant throughout the life course, since low self-control interacts with opportunity in producing crime, age variations in opportunity could affect the distribution of criminal behavior. Aging implies modifications in life styles, so criminal opportunities present for youth may decline as they grow older. Hence, the age effect could be explained by a variable from Gottfredson and Hirschi's own theory.

   3. NON-INTERACTION

      Of the three Hirschi-Gottfredson age-related hypotheses, the one concerning non-interaction has received the most attention. Several lines of work provide relevant evidence, some of it indirect and suggestive and some direct. Consider first, the indirect, suggestive evidence.

      Since, according to this hypothesis the causes and correlates of crime are the same at all ages, it follows that they must appear early (because crime, as Gottfredson and Hirschi define it, can be manifest even by children(25)) and operate throughout life. Therefore, research evaluating whether conditions present or established in childhood have long range stable effects on criminal behavior bears on the...