Pediatric Annals

The Psychophysiology of Child Misconduct

Angela Scarpa, PhD; Adrian Raine, DPhil

Abstract

It is not uncommon for youngsters to test the limits of authority and break the mies set for them, and so it may seem, as Socrates proposed, that "all youth are reckless." This generalization is a myth, however, because the majority of children and adolescents develop in positive and socialized ways. It is uncommon for children and adolescents to engage in serious rule-breaking repeatedly. It is this small percentage of children, approximately 2% to 6% of the general population, that is of particular concern.1

The antisocial behavior of these children tends to remain stable over time and lead to myriad associated problems such as physical injury, academic underachievement, peer rejection, exacerbated family conflict, and psychopathology. Moreover, this small number of children contributes to a disproportionately large number of antisocial acts. For example, statistics indicate that approximately 50% of all violent crimes in the United States are perpetrated by 5% of the child and adolescent subpopulation.2

A similar pattern of antisocial behavior in children has been identified in psychiatric literature and is called conduct disorder. Conduct disorder reflects a repetitive and persistent pattern of behavior in children and adolescents that violates the rights of others. Prevalence rates range from approximately 6% to 16% for boys and 2% to 9% for girls in the general population of children and adolescents. Criteria for the disorder, as defined by the Diagnostic and Statistical Manual for Mental Disorders, fourth edition (DSM/V),3 include an array of behaviors in four general categories: aggression toward people and animals, property destruction, deceitfulness or theft, and serious rule violations.

Conduct disorder is further broken down into two types, childhood-onset and adolescent-onset, based on the age of symptom onset. Childhood-onset represents those children for whom at least one symptom appears before age 10. Adolescent-onset represents those for whom no symptom is present before age 10. This typing is based on studies on development of antisocial behavior from childhood to adulthood, which suggest a better prognostic picture for the patient with adolescent-onset type.1

FOCUS ON PSYCHOPHYSIOLOGY

For the remainder of this article, we refer specifically to children and adolescents who engage in repetitive, impairing, and long-lasting antisocial behavior that is characteristic of conduct disorder. Although we acknowledge the important role of psychosocial experiences in the development of this disorder, we argue that it is partly the result of a biological dysfunction within the child, reflected in psychophysiological parameters. Such biological dysfunction is beyond the control of the child and may be viewed as a handicap or learning disability that the child must struggle to overcome.

A growing body of literature suggests biological differences may predispose a person to antisocial behavior. These include a wide range of findings on genetics, biochemistry, neuropsychology, brain imaging, and psychophysiology.4"6 These factors often interact with environmental events in a dynamic interplay.7,8 This article focuses on one area of biological influences on child antisocial behavior - psychophysiology. Psychophysiology involves the study of cognitions, emotions, and behavior as related to physiological principles and events (ie, the mind-body relationship), typically using noninvasive measures.9 This article reviews the major psychophysiological findings and theories regarding antisocial behavior in children and adolescents, with a specific focus on heart rate, skin conductance (SC), and electroencephalogram (EEG) measures.

Because antisocial behavior encompasses a wide range of behaviors and diagnoses, not all studies have determined the existence of conduct disorder in the participants. Other constructs that have been studied are childhood aggression. violence, and delinquency. Studies of delinquency include acts ranging from vandalism to murder. Studies of aggression and conduct disorder include behaviors that are not necessarily illegal (eg, lying, slapping, pushing) or individuals who have…

It is not uncommon for youngsters to test the limits of authority and break the mies set for them, and so it may seem, as Socrates proposed, that "all youth are reckless." This generalization is a myth, however, because the majority of children and adolescents develop in positive and socialized ways. It is uncommon for children and adolescents to engage in serious rule-breaking repeatedly. It is this small percentage of children, approximately 2% to 6% of the general population, that is of particular concern.1

The antisocial behavior of these children tends to remain stable over time and lead to myriad associated problems such as physical injury, academic underachievement, peer rejection, exacerbated family conflict, and psychopathology. Moreover, this small number of children contributes to a disproportionately large number of antisocial acts. For example, statistics indicate that approximately 50% of all violent crimes in the United States are perpetrated by 5% of the child and adolescent subpopulation.2

A similar pattern of antisocial behavior in children has been identified in psychiatric literature and is called conduct disorder. Conduct disorder reflects a repetitive and persistent pattern of behavior in children and adolescents that violates the rights of others. Prevalence rates range from approximately 6% to 16% for boys and 2% to 9% for girls in the general population of children and adolescents. Criteria for the disorder, as defined by the Diagnostic and Statistical Manual for Mental Disorders, fourth edition (DSM/V),3 include an array of behaviors in four general categories: aggression toward people and animals, property destruction, deceitfulness or theft, and serious rule violations.

Conduct disorder is further broken down into two types, childhood-onset and adolescent-onset, based on the age of symptom onset. Childhood-onset represents those children for whom at least one symptom appears before age 10. Adolescent-onset represents those for whom no symptom is present before age 10. This typing is based on studies on development of antisocial behavior from childhood to adulthood, which suggest a better prognostic picture for the patient with adolescent-onset type.1

FOCUS ON PSYCHOPHYSIOLOGY

For the remainder of this article, we refer specifically to children and adolescents who engage in repetitive, impairing, and long-lasting antisocial behavior that is characteristic of conduct disorder. Although we acknowledge the important role of psychosocial experiences in the development of this disorder, we argue that it is partly the result of a biological dysfunction within the child, reflected in psychophysiological parameters. Such biological dysfunction is beyond the control of the child and may be viewed as a handicap or learning disability that the child must struggle to overcome.

A growing body of literature suggests biological differences may predispose a person to antisocial behavior. These include a wide range of findings on genetics, biochemistry, neuropsychology, brain imaging, and psychophysiology.4"6 These factors often interact with environmental events in a dynamic interplay.7,8 This article focuses on one area of biological influences on child antisocial behavior - psychophysiology. Psychophysiology involves the study of cognitions, emotions, and behavior as related to physiological principles and events (ie, the mind-body relationship), typically using noninvasive measures.9 This article reviews the major psychophysiological findings and theories regarding antisocial behavior in children and adolescents, with a specific focus on heart rate, skin conductance (SC), and electroencephalogram (EEG) measures.

Because antisocial behavior encompasses a wide range of behaviors and diagnoses, not all studies have determined the existence of conduct disorder in the participants. Other constructs that have been studied are childhood aggression. violence, and delinquency. Studies of delinquency include acts ranging from vandalism to murder. Studies of aggression and conduct disorder include behaviors that are not necessarily illegal (eg, lying, slapping, pushing) or individuals who have never been charged with or convicted of a crime. The psychophysiological findings reviewed in this article are in relation to any of these antisocial expressions. As such, they can be considered pervasive across many different kinds of child misconduct, but also increasingly need to be clarified.

A DEVELOPMENTAL PERSPECTIVE

When discussing the psychophysiology of child misconduct, it becomes important to understand how such behavior changes from a developmental perspective. A longitudinal study of inner-city children and adolescents was designed to track profiles of children as they progress toward serious juvenile delinquency.10 A primary conclusion from this work is that these children begin with minor behavior problems in early childhood that develop into more serious problems in later childhood and adolescence. More specifically, the study identified three developmental pathways to delinquency from childhood to adolescence. In the first pathway, the authority-conflict pathway, children exhibit stubborn behavior followed by defiance, such as refusal and disobethence followed by authority avoidance including truancy from school, running away from home, and staying out late. In the covert pathway, children escalate from minor concealed behaviors, such as shoplifting or frequent lying, to property damage and more serious property crimes, such as burglary and theft. In the overt pathway, children progress from minor expressions of aggression (eg, annoying, bullying others) to increasingly serious physical fighting and finally to violent acts such as assault and rape. While many children exhibit the described minor behavior problems in early childhood, only a small proportion of children will progress to more serious levels.

Developmental studies such as this one help clinicians understand the progression of child misconduct and remind them that serious antisocial behavior does » not develop spontaneously. Rather, these children display a chronic course of misconduct with warning signals from early in development.

A similar conclusion was drawn by Moffitt1 in a study on developmental course of delinquent behavior. Two clusters of children and adolescents were identified and used as the basis for the childhood-onset and adolescent-onset typology for conduct disorder described in DSM-IV? These groups of antisocial ^ children and adolescents were termed "life-course persistent" and "adolescencelimited," respectively. Life-course persistent antisocial behavior begins in childhood and persists to adulthood. The children and adolescents in this group account for approximately 7% of the general population. These children are more likely to be aggressive, drop out of school, and have comorbid attentiondeficit/hyperactivity disorder, neuropsychological problems, and family conflict Adolescence-limited antisocial behavior, however, begins in adolescence and does not persist It is reported in 20% to 60% of all adolescents and therefore is more common, involves less aggressive offenses, \ and is primarily associated with the adolescent's influence by deviant peers.

In summary, the work of Loeber10 suggests that child misconduct starts early and progresses to more serious transgressions in a small proportion of children. The work of Moffitt1 also identified a subset of antisocial children and adolescents who display a chronic pattern of misconduct throughout their lives. The relevance of these developmental findings to the study of psychophysiology is the implication that biological risk factors, when present, are especially connected to earlyonset, life-course-persistent antisocial behavior. In support of this notion, low resting heart rate, one of the best-replicated psychophysiological findings in antisocial youth, has been found particularly in those in the life-course-persistent category. ' ' Another implication is that because a Hfe course of antisocial behavior often begins with relatively minor transgressions, the majority of findings in young children will operationally reflect milder forms of antisocial behavior (eg, mild aggression, oppositionality, disruptiveness), although these milder forms of behavior should and do predict more serious behavior in longitudinal studies.12"14

PSYCHOPHYSIOLOGICAL FINDINGS IN CHILD MISCONDUCT

As mentioned previously, psychophysiology is defined as the study of relationships between physiological measures with psychological states and processes. The most common measures in the study of antisocial behavior have been electrodermal, cardiovascular, and cortical. These measures are particularly relevant to psychological interpretations of behavior because they are connected to concepts such as learning, cognition, emotion, and arousal.

Theoretical Interpretations

The psychophysiological findings detailed in this article generally indicate reduced electrodermal, cardiovascular, and cortical arousal functioning - the physical reaction associated with alertness and the fight-flight response - in disruptive children. The causal explanation for this primary finding is yet unknown. Several theories have been suggested, however, and they need not be viewed as mutually exclusive.

One theory links reduced arousal levels with poor socialization to punishment. Eysenck15 argued that the socialization process and development of a conscience stem from a set of classically conditioned, negative emotional responses to situations that have previously led to punishment. In this way, socialized individuals develop a feeling of uneasiness at even contemplating antisocial behavior, presumably because such thoughts elicit representations of punishment earlier in life. Furthermore, arousal levels are related to conditionability; low levels of arousal predispose to poor conditionability and high levels to good conditionability. Thus, psychophysiological underarousal represents a lack of anticipatory fear to mild or moderate Stressors, leading to poor socialization from punishment or reduced effectiveness of conditioning.

On a related note, autonomie underarousal may reflect a disinihibited temperament Kagan16 reported on two styles of temperament, inhibited and uninhibited, based on a tendency to withdraw or interact consistently during a wide variety of novel experimental situations. Uninhibited children are especially bold or fearless in novel situations. This tendency has been found to be relatively stable from age 21 months to 8 years. Inhibited children have heightened and more stable heart rate relative to uninhibited children. Thus, reduced autonomie arousal in infancy may predispose to exploratory behavior and a disinhibited or bold temperamental style that can predispose to later externalization of behavior problems, including aggression and hyperactivity. Consistent with this possibility, a series of studies in a sample of children from Mauritius reported that inhibited or uninhibited temperament remains stable17 from ages 3 to 11. Those children with disinhibited temperaments exhibited reduced resting SC and heart rate levels relative to those with inhibited temperament, !8 and low resting heart rate at age 3 predicted aggression19 at age 1 1.

Another theory suggests the relationship between arousal and functioning follows an inverted-U shape: there is an optimal level of arousal at which an organism functions best and feels most comfortable,20 but at low or high levels, functioning and comfort decrease. Thus, at these suboptimal levels, patients will attempt to restore themselves to an optimal level of functioning. It is theorized that chronic levels of underarousal will lead to stimulation-seeking behavior in an attempt to raise arousal levels to optimal states. Stimulation seeking, in turn, predisposes to risk-taking behavior and a greater likelihood of associated antisocial behavior.21 Related to these three theories, findings indicate that both fearlessness and stimulation-seeking at age 3 predicted aggressive behavior22 at age 11. Others have theorized that chronically antisocial people are characterized by high vagai tone, which Venables23 termed "vagotonia ." Vagotonia is defined as a predominance of parasympathetic relative to sympathetic autonomie nervous system activity cause by parasympathetic activity being primarily mediated by the vagus nerve. The parasympathetic system has a restorative, adaptive function that allows the organism to recover from activating and stressful experiences. Normally, it is associated with a passive coping response to mildly stressful situations, which would prepare an organism for disengagement and inactivity in a threatening situation. Because of its parasympathetic influence, high vagai tone is also thought to reflect emotion-regulation capacity because an individual is able to selfsoothe when experiencing a strong emotion.24-25 It is hypothesized, however, that such passive emotional withdrawal, increased control of emotionality, immobilization, and resulting muscular relaxation may attenuate painful experiences, which again may lead to an insensitivity to socializing punishments.

In addition, it has been speculated that underarousal reflects specific deficits in brain structure and functioning.4 Frontal areas of the brain, in particular, have been linked to reduced SC activity,26 and it has been suggested that prefrontal brain dysfunction possibly underlies the reductions in SC activity found in antisocial samples.27 Thus, even in the absence of visible lesions, some subtle impairment in frontal lobe functioning may lead to antisocial behavior by interrupting fear conditioning, autonomie arousal regulation, emotional control, and executive cognitive functioning (eg, planning, decision making, consideration of future consequences to guide behavior). Damasio28 has termed this "acquired sociopathy."

Heart Rate and Child Misconduct

Heart rate reflects both sympathetic (ie, activation) and parasympathetic (ie, conservation) nervous system activity. It can be measured both tonically, using the beats per minute at rest, or phasically, using change in response to a stimulus. As described previously, tonic heart rate may reflect fearlessness or disinhibition16,18 or a pattern of stimulation-seeking behavior.21 One of the best-replicated psychophysiological findings is that of reduced resting heart rate in disruptive and antisocial youth. In his review of this topic, Raine4 noted that of 14 relevant studies, there were no failures to replicate the finding of reduced-resting heart rate in antisocial groups.

Low heart rate is a robust marker independent of cultural context, with the relationship having been established in England,29 Germany,30 New Zealand," the United States,31 Mauritius,19 and Canada.32 It is also diagnostically specific and multiple potential confounding factors have been controlled.19 Furthermore, in a recent study of childhood aggression, a negative relationship was found between heart rate and proactive (ie, goal driven), but not reactive (ie, defensive, impulsive), forms of aggression,33 suggesting heart rate underarousal may be specific to unemotional and instrumental displays of aggression.

When measured phasically, accelerations in heart rate to a stimulus are thought to reflect sensory rejection or "tuning out" of noxious environmental events, while decelerations are thought to reflect sensory intake or an environmental openness. As such, accelerations in heart rate in response to a stimulus are considered defensive responses and decelerations are considered orienting responses. One prospective study found that reduced heart rate and SC orienting to neutral tones in adolescents predicted a later criminal outcome.13 The pattern of heart rate and SCorienting deficits in future criminals may reflect a general failure to allocate attentional resources to stimulus processing, especially if the stimulus is not very interesting, which is consistent with theories of frontal or neuropsychological deficits.34

Another cardiovascular measure that is gaining popularity is heart rate variability (HRV), which is the normal variation in interval that occurs between heart beats as a function of respiration. Whereas heart rate has both sympathetic and parasympathetic influences, HRV is vagally mediated and controlled primarily by the parasympathetic branch of the autonomie nervous system. In other words, the parasympathetic nervous system helps to slow the heart, which creates more beatto-beat variability in HR. As such, high HRV is a reflection of vagotonia and thought to reflect emotion regulation capacity.24 Contrary to theories of vagotonia, however, the few studies of HRV in children have shown inverse relationships between antisocial behavior and HRV. These studies indicate that reduced HRV, and therefore decreased vagai tone, is related to increased levels of aggressive behavior in boys exposed to marital conflict,25 externalizing behavior in younger brothers of adjudicated delinquents,35 and a composite of antisocial behavior in inner-city male adolescents.32

The inconsistency in findings between low tonic heart rate and decreased HRV is difficult to reconcile. One possibility is that findings differ according to the kind of antisocial behavior that is assessed. For example, in a previous review, it was argued that autonomie underaomsal is related primarily to proactive displays of aggression that are relatively unemotional and instrumental in nature, while autonomie oveneactivity is related to reactive displays of aggression that are more emotional and impulsive in nature.6 Thus, low heart rate may characterize primarily proactive aggression, while decreased HRV may characterize primarily reactive aggression. This would be consistent with the theory that decreased HRV is a reflection of decreased emotion regulation ability and consequent difficulties with selfcontrol and negative emotionality,24

Two recent studies support this possibility. In an unselected sample of children and adolescents from a metropolitan area, decreased HRV was found to be related to poor impulse control in boys.33 In a study designed to examine reactive and proactive childhood aggression, low heart rate and increased HRV were found to be specifically related to proactive aggression, suggesting that vagotonia may reflect a style of aggression that involves a high degree of emotional control.35

In summary, while some types of childhood misconduct may be related to underarousal, others may be related to deficient emotion-regulatory capacity associated with high negative affect.

Skin Conductance (SC) and Child Misconduct

SC measures the electrical conductance of a small current that is passed through two electrodes, usually placed on the hand, as sweat rises in the glands. As with heart rate, SC can be measured both tonically and phasically. Typical tonic measures of SC include SC level and the number of nonspecific SC fluctuations. Nonspecific SC fluctuations are changes in SC that look like phasic orienting responses but do not occur in response to a known stimulus. Both SC level and nonspecific SC fluctuations are thought to reflect a baseline level of physiological sympathetic arousal and often have been associated with fear emotions in the fightor-flight response.

With regard to SC underarousal, both SC level and nonspecific SC fluctuations have been found to be reduced in antisocial groups in a number of studies, although this has not been consistent. The findings are primarily found in uninstitutionalized subjects with mild forms of aggression or other antisocial behavior. However, the findings seem to predict later institutionalization. For example, in a study of children with behavior disorders, low SC level measured at age 11 predicted institutionalization37 at age 13. Furthermore, findings of a reduced number of nonspecific SC fluctuations at age 15 predicted criminal behavior 9 years later.12 Raine and colleagues suggested that this pattern, along with low resting HR, reflected autonomie underarousal in future criminals. More recently, a study of 335 boys from the community who selfreported with serious delinquency found this classification was characterized by low SC level measured at age 16, consistent with the notion of reduced SC arousal in antisocial boys.21 Findings of reduced SC activity may be specific to children with conduct disorders who display a pattern of callous, unemotional traits.38

Regarding phasic SC activity, changes in the electrical activity of the skin generally occur in response to the presentation of novel stimuli in an environment. For example, the presentation of a new tone generally causes an orienting response that is accompanied by increased electrical activity in the skin, and thus, a change in levels - the SC-orienting response. This response also increases if a novel stimulus is recognized as significant and needs further processing. Thus, the SCorienting response is a useful index of how one's attention to and processing of novel environmental stimuli.34

In his review, Raine4 concluded that deficits in the SC-orienting response have been observed consistently in patients who display both antisocial behavior and features of schizotypal personality disorder, which is characterized by odd behavior, interpersonal deficits, and cognitive or perceptual distortions. A more recent study supported this conclusion, finding adolescents with schizotypal tendencies who later displayed criminal behavior were characterized by reduced SC-orientuig responses relative to those who were nonschizotypal or did not display criminal behavior.39 It seems that SC-orienting-^esponse deficits may be spécule to schizotypal criminals. Raine et al.26 found a significant relationship between reduced prefrontal cortex area measured by magnetic resonance imaging and fewer orienting responses in normal subjects. The finding of fewer SC-orienting responses in schizoid and schizotypal antisocial adolescents may indicate frontal dysfunction in this particular subgroup.

Other findings, however, have indicated increased SC reactivity in relation to antisocial behavior in specific contexts. For example, a study of children in second grade found reactive, but not proactive, aggression was positively related to SC reactivity as well as to angry, nonverbal behaviors in response to a frustration challenge.40 Also, a prospective study found reduced SC-orienting responses in 3-year-old children from high social classes were related to their aggressive behavior at age 1 1 . This result was not found in children from low social classes.41

SC has also been used to assess Eysenck's15 theory that antisocial people may be characterized by poor classical conditioning. In these studies, a neutral, nonaversive tone is presented to the subject, followed a few seconds later by either a loud tone or an electric shock. The key measure is the size of the SC response elicited by the neutral, nonaversive tone after a number of pairings of the neutral tone with the loud tone and the neutral tone with the shock. Reduced SC conditioning seems to be one of the strongest SC findings to date relative to antisocial populations. Hare42 and Raine4 collectively reported this finding in 19 out of 20 studies. It seems that all of these studies used adult samples, however, with the exception of one that found reduced SC conditioning in children with conduct disorder from high but not low socialclass backgrounds. Thus, further studies of SC classical conditioning in children and adolescents are needed.

In summary, the strongest SC finding with respect to child misconduct involves SC underarousal in terms of reduced SC levels and nonspecific SC fluctuations. This may particularly characterize callous, unemotional traits in antisocial children and adolescents, and these traits have been associated with increased stimulation-seeking.43 Reduced SC-orienting responses may be specific to antisocial adolescents who also have schizotypal personality features or come from high social-class backgrounds. The one finding of SC conditioning in children is consistent with the larger literature showing poor classical conditioning in relation to antisocial behavior.

Electroencephalogram (EEG) and Child Misconduct

EEG reflects the electrical activity of the brain recorded from electrodes placed at different locations on the scalp according to the standardized International 10-20 system. EEG can be broken down into different frequency components, most commonly delta (O to 4 Hz), theta (4 to 8 Hz), alpha (8 to 12 Hz), and beta (13 to 30 Hz). EEG frequency has been aligned with a continuum of consciousness - delta is associated with sleep, theta is associated with drowsiness and low levels of alertness, alpha is associated with relaxed wakefulness, and beta is associated with alertness and vigilance. As such, individuals with a predominance of delta, theta, or slow alpha activity would be viewed as having relatively reduced levels of cortical arousal, while those with relatively faster alpha and beta activity would be viewed as relatively more aroused.

Early studies indicated more slowwave EEG activity in antisocial boys who were violent and institutionalized, although it was unclear if the slowing was a predictor for or a consequence of violent fights.44 Since then, several prospective longitudinal studies found EEG slowing in adolescence predicted later criminal offending.12,45,46 In addition, EEG activity localized particularly to the left frontal area was found to be inversely related to restrospective reports of antisocial personality disorder and childhood behavior problems.47 Consistent with the brain dysfunction theory, Volavka44 speculated EEG slowing in childhood reflects brain injuries obtained at various developmental stages. These subtle brain injuries, in turn, could impair the child's ability to learn to avoid aggressive behavior and result in disinhibited behavior, especially if the injuries involved the frontal cortex.

EEGs may also be assessed qualitatively through visual inspection to determine more broadly whether results are normal or abnormal. In such clinical scoring, approximately 10% to 15% of normal subjects have abnormal EEGs; this is important when considering rates of abnormalities reported hi antisocial populations. In his review, Volavka44 reported qualitative EEG abnormalities have been noted primarily in incarcerated or hospitalized violent adolescents but not in delinquents who were not selected for violence. Interestingly, a study of aggressive people from the community who were not incarcerated, most of whom ranged in age from 4 to 20, found an overall rate of EEG abnormalities of 6.7%, similar to the general population.48 This finding suggests that abnormal EEGs may pertain specifically to "unsuccessful" violent individuals, who are unable to avoid detection and thus cannot evade incarceration.

When an EEG is used to measure phasic activity, it is referred to as the eventrelated potential (ERP), which reflects averaged changes of electrical activity of the brain in response to specific stimuli. ERP responses typically follow a sequence of early, middle, and late components that are thought to reflect the psychological processes of environmental filtering, cortical augmenting, and attention, respectively.

ERP studies of antisocial behavior have primarily involved psychopathic populations, and a review of this literature (conceptually broken down into early, middle, and late latency studies) was done by Raine.49 There is reason to believe, however, that impaired EEG and ERPs may reflect early risks for later criminal behavior. It was also found that criminals versus noncriminals had significantly more slow-frequency EEG theta activity and larger amplitude of the N 1 OO ERP (an early ERP component) to target stimuli as measured 9 years earlier.12·14 These findings are consistent with notions of underarousal and enhanced early stimulus attention in criminals and psychopaths.

PSYCHOPHYSIOLOGICAL STUDIESOFCRIME

Raine and colleagues12"14 conducted a series of prospective psychophysiological analyses in 15-year-old male schoolchildren for whom official records indicated a criminal offense by age 24. The first in this series indicated that, relative to noncriminal controls, the future criminals exhibited electrodennal, cardiovascular, and cortical underarousaJ reflected in significantly fewer nonspecific SC fluctuations, lower resting HR, and more slowfrequency EEG theta activity.12 This is the first study to show physiological underarousal in three independent psychophysiological response systems. In the second analysis of this series, future criminals were found to be characterized at age 15 by a reduced number of SC- and heartrate-orienting responses to a series of 65 Db tones.13 Furthermore, 31% of criminals were characterized by electrodermal nonresponding - no response to any of the orienting stimuli - in contrast to a rate of only 10% in noncriminal controls. Findings from the third analysis in the series indicated significantly larger NlOO ERPs to the attend stimulus in future criminals.14 The authors interpreted this finding as suggesting enhanced early stimulus-set attention in passive-attend situations in adolescents who would become criminals.

These prospective findings are impressive in that they generally support the SC, heart rate, EEG, and ERP findings from cross-sectional studies reported previously in one population of subjects from the same laboratory. They imply psychophysiological dysfunction in children and adolescents predates later criminal behavior and may reflect some early processes in misconduct that lead to more serious antisocial outcome.

CONCLUSIONS

A great deal of evidence has accumulated on psychophysiological correlates of child misconduct. In particular, low autonomie and central nervous system arousal has been implicated in terms of reduced resting heart rate and SC measures and increased slow-wave EEG activity. l2 Low resting heart rate, in particular, is one of the best-replicated psychophysiological measures that characterize antisocial behavior. Evidence is most supportive of theories suggesting that such underarousaJ indexes a fearless, disinhibited temperament, or a tendency toward stimulation-seeking behavior, characteristics that have been found to be predictive of antisocial outcomes.22 Underarousal could also reflect a deficiency in classical conditioning to punishment and thus interfere with the socialization process. However, evidence for reduced classical conditioning, although strong in adult antisocial populations, is lacking in child studies.

Findings of reduced SC-orienting responses in antisocial adolescents with schizotypy and EEG abnormalities localized to the frontal lobes have implicated frontal dysfunction in antisocial children and adolescents, particularly in relationship to violence and institutionalization.27'44,45 Damage to this area of the brain has been associated with personality and behavioral characteristics that are similar to what is observed in psychopathic patients, thus leading Damasio28 to coin the term "acquired sociopathy" in patients who suffer these sorts of injuries. Even in the absence of visible lesions, there may exist some subtle impairment in frontal-lobe functioning that may lead to antisocial behavior by interrupting fear conditioning, autonomie arousal regulation, emotional control, and executive cognitive functioning.

Some contrasting findings of increased SC reactivity40 and decreased HRV32-35 in relation to some antisocial behavior in children and adolescents suggest further clarification of the underlying physiological dysfunction is needed. These findings are often associated with situations and analog-aggression tasks that involve provocation, anger, and heightened negative emotionality, providing support to the suggestion that psychophysiological profiles will differ depending on the type of antisocial behavior studied (eg, reactive versus proactive aggression) and the temperamental qualities expressed (eg, negative emotionality versus fearlessness).6 Indeed, hi light of the extreme variation in antisocial behaviors manifested and studied, it would be overly simplistic to assume they are all characterized by the same underlying biological dysfunction and concomitant psychophysiological correlates.

SUMMARY

Psychophysiological evidence supports the notion that serious and persistent childhood misconduct is symptomatic of an internal dysfunction that dynamically interacts with other psychological and social causes. Childhood misconduct is a complex phenomenon with multiple causes and no easy solutions. Rather than think our civilization is doomed, however, we should realize that the great majority of our children grow up to be sociable and lawabiding individuals. For j the others, we are afforded optimism that this problem can be minimized as we gain a more complete understanding of the interplay among biological, psychological, and social risks, and through the consequent refinement of interventions.

REFERENCES

1. Moffitt TE. Adolescence-limited and lifecourse persistent antisocial behavior a developmental taxonomy. Psychol Rev. 1993;IOO(4):674-701.

2. American Psychological Association. Summary report of the American Psychological Association Commission on Violence and Youth. Vol. 1. Washington, DC: American Psychological Association; 1993.

3. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Publishing Inc.; 1994:85-91.

4. Raine A. The Psychopalhology of Crime: Criminal Behavior as a Clinical Disorder. San Diego, CA: Academic Press; 1993.

5. Scarps A, Raine A. Biology of wickedness. PsychiatrAnn. 1997;27:624-629.

6. Scalpa A, Raine A. Psychophysiology of anger and violent behavior. Psychiatr Clin North Am. 1997;20(2):375-394.

7. Raine A- Biosocial studies of antisocial and violent behavior in children and adults: a review. J Abnorm Child Psychol. 2002;30(4):311-326.

8. Scarpa A, Raine A. The psychophysiology of antisocial behavior interactions with environmental experiences. In: Walsh A, Ellis L, eds. Biosocial Criminology: Challenging Environmentaiism's Supremacy. New York, NY: Nova Science; 2003:209-226.

9. Cacioppo JT, Tassinary LG. Psychophysiology and psychophysiological inference. In: Cacioppo JT, Tassinary LG, eds. Principles of Psychophysiology: Physical, Social, and Inferential Elements. New York. NY: Cambridge University Press; 1990:3-33.

10. Loeber R, Wung P, Keenan K, et al. Developmental pathways in disruptive child behavior. Dev Psychopathol. 1993;5(I-2):103-133.

11 . Moffitt TE, Caspi A. Childhood predictors differentiate life-course persistent and adolescent limited pathways among males and females. Dev Psychopathol. 2001;13(2):355-375.

12. Raine A, Venables PH, Williams M. Relationships between CNS and ANS measures of arousal at age 15 and criminality at age 24. Arch Gen Psychiatry. 1990;47(11):1003-1007.

13. Raine A. Venables PH, Williams M. Orienting and criminality: a prospective study. Am J Psychiatry. 1990;147(7):933-937.

14. Raine A, Venables PH, Williams M. Relationships between Nl, P300 and CNV recorded at age 15 and criminal behavior at age 24. Psychophysiology. 1990;27(5):567-575.

15. Eysenck HJ. Crime and Personality. 3rd ed. St. Albans, England: Paladin Press; 1977.

16. Kagan J. Temperamental contributions to social behavior. American Psychologist. 1989;44(4):668-674.

17. Scarpa A, Raine A, Venables PH, Mednick SA. The stability of inhibited/uninhibited temperament from ages 3-1 1 years in Mauritian children. J Abnorm ChiltJ Psychol. i995;23<5):607-618.

18. Scarpa A, Raine A, Venables PH, Mednick SA. Heart rate and skin conductance in behavioralIy inhibited Mauritian children. J Abnorm PsychoL 1997;106(2):182-190.

19. Raine A, Venables PH. Mednick SA. Low resting heart rate at age 3 years predisposes to aggression at age 1 1 years: findings from the Mauritius Joint Child Health Project J Am Acad Child Adátese Psychiatry. 1997;36(10):1457-1464.

20. Quay HC. Psychopathk personality as pathological stimulation-seeking. Am J Psychiatry. 1965; 122: 180- 183.

21. Gatzke-Kopp LM, Raine A, Loeber R, Stouthamer-Loeber M, Steinhauer SR. Serious delinquent behavior, sensation seeking, and electrodermal arousal. J Abnorm Child Psychol. 2002;305):477486.

22. Raine A, Reynolds C, Venables PH, Mednick SA, Farrington DP. Fearlessness, stimulationseeking, and large body size at age 3 years as early predispositions to childhood aggression at age 1 1 years. Arch Gen Psychiatry. 1998;55(8):745-751.

23. Venables PH. Psychophysiology and crime: theory and data. In: Moffitt TE, ed. Biological Contributions to Crime Causation. Dordrech, The Netherlands: Kluwer Academic Publishers; 1988.

24. Porges SW, Doussard-Roosevelt JA, Maio' AK. Vagai tone and the physiological regulation of emotion. Monogr Soc Res Child Dev. 1994;59(2-3}:167-186.

25. Katz LF, Gottman JM. Vagai tone protects children from marital conflict. Development & Psychopafhology. 1995;7(l):83-92.

26. Raine A, Reynolds GP, Sheard C. Neuroanatomical mediators of electrodermal activity in normal human subjects: a magnetic resonance imaging study. Psychophysiology. 1991;28(5):548-558.

27. Raine A, Lencz T, Bihrle S, LaCasse L, Colletti P. Reduced prefrontal gray matter volume and reduced autonomie activity in antisocial personality disorder. Arch Gen Psychiatry. 2000;57(2):119-127.

28. Damasio AR. Descartes' Error: Emotion, Reason, and the Human Brain. New York, NY: Avon Books; 1994.

29. Farrington DP. Implications of biological findings for criminological research. In: Mednick SA, Moffitt TE, Stack SA. The Causes of Crime: New Biological Approaches. Cambridge, England: Cambridge University Press; 1987:42-64.

30. Schmeck K. Poustra F. Psychophysiologische Reacktionsmuster und psychische auffalligkeiten im kindesalter. In: Baumann P, ed. Bioloogische Psychiatrie der Gegenwart. Vienna, Austria: Springer-Verlag; 1993.

31. Rogeness GA, Cepeda C, Macedo CA, Fischer C, Harris WR. Differences in heart rate and blood pressure in children with conduct disorder, major depression, and separation anxiety. Psychiatry Res. 1990;33(2): 199-206.

32. Mezzacappa E, Tremblay RE, Kindton D, et aL Anxiety, antisocial behavior, and heart rate regulation in adolescent males. J Child Psychol Psychiatry. 1997;38(4):457-469.

33. Van Voorhees E, Scarpa A. Psychophysiological variables in childhood proactive and reactive aggression. Psychophysiology. 2002;39(Suppl 1):82.

34. Dawson ME, Blion DL, ScheD AM. Is eucitation of the autonomie orienting response associated with the allocation of processing resources? Psycoopbysiology. 1989¿6(5):560572.

35. Pine DS, Wasserman GA, Miller L, et al. Heart period variability and psychopathology in urban boys at risk for delinquency. Psychophysiology. 1998;35(5):52 1-529.

36. Alien MT, Matthews KA, Kenyon KL. The relationships of resting baroreflex sensitivity, heart rate variability and measures of impulse control in children and adolescents. Ini J Psychophysiol. 2000;37(2):185-194.

37. Kruesi MJ, Hibbs ED, Zahn TP, Keysor CS. A 2-year prospective follow-up study of children and adolescents with disruptive behavior disorders: prediction by cerebrospinal fluid 5hydroxyindoleacetic acid, homovanillic acid, and autonomie measures? Arch Gen Psychiatry. 1992;49(6):429-435.

38. Lahey BB, Hart EL, Pliszka S, Applegate B, McBumett K. Neurophysiological correlates of conduct disorder a rationale and a review of research. J Clin Child Psychology. 1993;22: 141-153.

39. Raine A, Bihrle S, Venables PH, Mednick SA, Pollock V. Skin-conductance orienting deficits and increased alcoholism in schizotypal criminals. J Abnorm Psychol 1999;108(2}:299-306.

40. Hubbard JA, Smithmyer CM, Ramsden SR, et al. Observational, physiological, and self-report measures of children's anger relations to reactive and proactive aggression. Child Development. 2Q02;13(4): 1101-1 118.

41. Raine A. Reynolds C, Venables PH, Mednick SA. Biosocial bases of aggressive behavior in childhood: resting heart rate, skin conductance orienting, and physique. In: Raine A, Brennan PA, Farrington DP, Mednick SA, eds. Biosocial Bases of Violence. New York, NY: Plenum Publishing; 1997:107-126.

42. Hare RD. Electrodermal and cardiovascular correlates of psychopathy. In: Hare RD, Schalling D, eds. Psychopathic Behavior: Approaches to Research. New York, NY: Wiley; 1978:107-144.

43. Frick PJ, OBrien BS, Wootton JM, McBumett K. Psychopathy and conduct problems in children. J Abnorm Psychology. 1994;103(4):700-707.

44. Volavka J. Neurobiology of Violence. Washington, DC: American Psychiatric Press; 1995.

45. Mednick SA, Volavka J, Gabrielli WF, Itil T. EEG as a predictor of antisocial behavior. Criminology. 1982; 19:2 1 9-229.

46. Petersen KG, Matousek M, Mednick SA, Volavka J, Pollock V. EEG antecedents of thievery. Acta Psychiatrica Scandinavia, 1982;65(5):33 1-338.

47. Deckel AW, Hesselbrock V, Bauer L. Antisocial personality disorder, childhood delinquency, and frontal brain functioning: EEC and neuropsychological findings. J Clin Psychol. 19%;52<6):639-650.

48. Riley TL. The electroencephalogram in patients with rage attacks or episodic violent behavior. MUMedicme. 1979;144<8):5I5-517.

49. Raine A. Evoked potentials and psychopathy. ha J PsychophysioL 1989;8(1):1-16.

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