eadlines and accompanying voyeurism have reduced the problem of youth violence to its simplest common denominator. Single-factor explanations abound, usually accompanied with single-digit finger-pointing. Blame is laid at the feet of the gun seller, the drug dealer, the parole officer, the absent parent. To paraphrase H. L. Mencken, for every problem there is a solution, which is neat, plausible, and wrong.

If a society is to seriously address problems of youth violence, it must seek to understand its causes and intervene without delay. If it prefers to promote violence, it can engage pollsters, pundits, and media experts to decry it while simultaneously advertising it. Eliminating youth violence will require stepping outside the narrowing and popularized frameworks that provide unidimensional and generally individualized explanations and, instead, thinking deeply about the transactional meaning of youth violence in a violent society.

Research investment on youth violence by the National Institutes of Health (NIH) has supported studies on correlates, consequences, prevention, and treatment of antisocial behavior. The social and behavioral sciences have tackled the problem of youth violence with a vengeance, and this work has yielded a vast amount of descriptive information about the manifestations of antisocial behavior, its prevalence and incidence, and the pattern of risk factors that place some children on trajectories that end in the adult criminal system. There is now ample consensus among social scientists that certain risks (such as academic failure, early psychiatric problems, and language delays) are highly correlated with poor outcomes. Many social scientists believe that the characteristics of children, families, and neighborhoods associated with later antisocial behavior syndromes can be specified and that the more persistent and difficult-to-treat behavior patterns are often established early. A resounding call for preventive efforts has hailed from many quarters.

Not surprisingly, when preventive actions are called for, schools become a focal point. A free, appropriate public education is guaranteed for all children. Children spend almost as much time in school as they do watching television. Moreover, when children have mental health needs, it is the schools that provide services, not the mental health system (Burns et al., 1995). Schools are the hub of many communities, particularly in rural areas, so it is understandable that if preventive efforts targeted towards early intervention are to succeed, schools must be involved.

At the same time, the host of social ills besieging children in this country, from homelessness to domestic violence to HIV to child neglect and abuse, place unprecedented pressures on schools to, in essence, become surrogate guardians for many children. Balancing the needs of these children against the mandate to educate and now to meet academic standards set by state agencies is a formidable task, and schools are finding their curricula bulging with special units on what are sometimes seen as nonacademic and irrelevant frills — social skills training, anger management, conflict resolution, and safe sex, to name a few.

In a recent review of the distribution of research grant emphases in the area of violence, several NIH institutes classified their studies into one of three categories: (a) preintervention studies, which included risk or protective studies, population-based epidemiological studies, or basic prevention development; (b) efficacy studies, which included laboratory trials of the impact of specific preventive or treatment interventions targeted at disruptive behavior disorders, including conduct disorder; and (c) effectiveness research, which included studies of the effectiveness, dissemination, or transportability of interventions into community (nonacademic) settings. Approximately three quarters of the grants fell into the category of preintervention studies. The remainder were thinly spread between studies of the efficacy of specific interventions and (even more thinly) studies of their effectiveness in diverse communities.

The articles in this special double issue are addressing the very important questions that characterize the latter two categories of study: the impact, efficacy, and effectiveness of violence prevention programs delivered in the schools and the organizational factors, including climate, culture, and context, that enable programs to have tenure beyond the life of the research teams who study them.

In fact, the articles here reverse the trend that has constituted what Felton Earls recently called "the implicit logic of violence prevention" (NIH, 1999). While in the past, theories and interventions were formulated on the assumption that individual behavior or attitudes needed to be the first target, followed by an outward expansion towards communities, Earls suggested that it is not only possible but necessary to reverse the logic. The strongest factors influencing behavior are extra-individual, not intrapsychic. Advances in research methods designed to assess the impact of social settings and social networks have made such techniques available for studies of community-level interventions. In fact, had these techniques and methods been available three decades ago when community activism was at its height, one wonders whether more progress might have been made in building an evidence base for community interventions to stem violence. Several of the articles in this double issue specifically address issues of community milieu, school climate, social interactional variables, and other "extra-individual" influences that affect the implementation and impact of evidence-based intervention programs.

A second corrective balance provided by this issue is the explicit contribution to the evidence base through inclusion of rigorously examined school service programs. The preventive and intervention programs demonstrate, through carefully crafted designs, clear reductions in youth violence and associated antisocial behaviors. This is noteworthy because the fugitive literature (i.e., not peer reviewed) is filled with anecdotal reports of poorly designed evaluations where outcomes are often positive but their meaning is unascertainable. Even worse, the majority of school programs currently in use across the country that are aimed at reducing violence in youth are completely untested, so outcomes of these programs are not even known.

This is an important corrective because the promotion of untested practices can be worse than harmless; it can be dangerous. Del Elliot (NIH, 1999) pointed out that 95% of programs being used to reduce violence in communities have no scientific evidence for their effectiveness. The dangers of implementing popular but undocumented services has been recently demonstrated. An important article by Dishion, McCord, and Poulin (1999) reported that peer group interventions (including counseling sessions and summer camps run and supervised by adults) significantly increased among high-risk adolescents such problem behavior as substance abuse, delinquency, and violence. They referred to this as "deviancy training" to denote the positive reinforcement that occurs in teen groups via laughter, social attention, and interest in deviant behavior, which promotes further socially maladaptive behaviors. They also pointed out the need for specificity in targeting interventions to treatment needs: Youth who are depressed and have no comorbid disruptive behavior disorders have been effectively treated in groups using cognitive behavioral interventions (Clarke et al., 1995). Given Dishion et al.'s findings, however, it would be unwise to aggregate youth with disruptive behavior problems in such group treatments.

These so-called negative findings are important not only in pointing practitioners away from bad practices, but also by advancing the science base in very fundamental ways. As Stephen Jay Gould pointed out, the idea of unilinear progress in science is false: "Science advances primarily by replacement, not by addition" (1981, p. 321). If science were linear, then negative findings or disproofs would hamper progress. But, in fact, this is not the case, as the example of deviancy training illustrates.

This issue contributes to the knowledge base on school services by focusing attention on programs with demonstrable impact and on the social context in which the programs are embedded. But as Burns pointed out (1999), although the evidence base is being strengthened, attention must be paid simultaneously to achieving consensus about the criteria to apply to the evidence base, to determine what constitutes evidence and what constitutes clinically significant outcomes. Such criteria are needed for determining when effective programs are ready to be taken to scale and on how grand a scale.

Establishing such criteria will require, among other aims, attention to the degree to which the body of knowledge addresses fundamental questions about causality. Although many theories in the social and behavioral sciences have been propounded over the past two decades to explain the origins of violence, theoretical progress on the causal bases of antisocial behavior has not occurred. Theories ranging from "risky shift" to "cognitive slippage" have come and gone. None have held sway or had staying power. Richters (1993; Richters & Cicchetti, 1997), whose penetrating work has pioneered new ways of thinking about these problems, pointed out that despite the multiplicative proliferation of theoretical models and descriptive information, progress has not occurred in understanding how the descriptive information about violence should be interpreted: Why do antisocial pathways develop for some children but not for others with the same risk profiles? Why does antisocial behavior remit or change direction in some? Why is such behavior difficult to treat once it has been established? One reason for the lack of progress may be that the methodological traditions, which consistently employ strategies for studying individual differences, presume causal homogeneity. That is, the study designs are crafted to test single multivariate theories, participants are recruited and classified into samples based on phenotypic similarities, and the same variables are assessed on all participants. Estimations of risk are formed on the basis of covariations across participants, and statistical covariation procedures are used to control for the possible influence of nuisance variables. Yet I have never met anyone who believes that violent, delinquent, or otherwise "antisocial" behaviors in children are causally homogeneous. Consequently, there is a mismatch between the methodological traditions widely followed in the social and behavioral sciences, which presume homogeneity, and the expectation that antisocial behavior problems are causally heterogeneous and that, in fact, multiple subtypes and trajectories exist.

Areas for further reflection
For further progress to be made in understanding, preventing, and treating youth violence, the typical response tends to be "more research is needed." No doubt. Yet, in an age when parenting is less available, when marriage has almost become a thing of the past, and when children are being turned into commodity machines, it may make sense to reflect, as Plotz (1999) pointed out, that America is obsessed with youth because corporations are obsessed with youth: early intervention means netting an eager consumer audience for life. If this is true, then youth violence will be gone only when it is no longer marketable to sell murder, rape, homicide, assault, or violent acts.

Nevertheless, there are many areas in which basic questions about youth violence cannot yet be answered. In addition to the absence of strong, testable, causal theories that take into account the subtypes of antisocial behavior, there are other areas that should be the target of further study.

1. Mechanisms. Early onset is an important predictor, yet late onset accounts for the largest percentage of violent behavior. The focus of most research to date has been on markers, not on underlying mechanisms or processes by which aggressive behavior develops. Similarly, no attention has yet been paid to the termination of delinquency, to why some youth divest themselves of delinquent acts and stop their involvement in violence.
    

2. Involvement in Gangs. This is a major risk factor, but almost no researchers have investigated either the mechanisms of transmission of risk whereby some children get involved and others resist, or the efficacy of existing programs for preventing involvement in gangs.
    

3. Positive Parenting Strategies. The risks associated with harsh parenting practices have been amply demonstrated to be predictive of later delinquency, but less attention has been paid to developing specific interventions that promote positive parenting practices in very young children. Such studies are needed.
    

4. Environmental Factors. Programs exist in neighborhoods, communities, and a variety of "host" environments. Little is now known about the ways in which different neighborhood environments moderate, accelerate, or exacerbate the effects of violence. Studies of the ways in which differences in resources affect a neighborhood's ability to mobilize efforts to respond to or reduce violence are especially needed. In addition, socialization processes extend beyond person-to-person exchanges. What aspects of environments socialize aggression? These are questions worthy of investigation.
    

5. Organizational Capacity. As effective interventions are becoming available, the next generation of studies will need to focus on the types of organizational capacities (e.g., strength of leadership, workplace flexibility, employee autonomy) that are necessary to support the implementation of these programs. Issues such as financial capacity, investment of stakeholders, organizational structure, and motivational sustainability are components of capacity that warrant attention.
    

6. Fidelity. Even effective treatments or services cannot be sustained if fidelity to the programs' principles and practices is not upheld. Studies are needed on how to sustain fidelity to treatment models, how to strengthen the quality of the program as delivered, how to maintain integrity as the intervention is implemented in local sites, how to judge when a modification will affect a program, and how much change is legitimate before it interferes with the integrity of the program.
    

7. Dissemination and Sustainability. The transportability of effective services into different schools or community settings is not automatic. An important new area of research involves attention to characteristics of communities, neighborhoods, organizations, schools, clinics, and other settings that will facilitate the long-term sustainability of effective services. Questions such as how much technical assistance to provide and for how long, how and when to certify trainers, and how or why policymakers do or do not adopt effective programs are components of this area of research. Important to this area of research are cost-benefit studies that employ full benefit analyses of programs. Insofar as studies of the effectiveness of services explicitly address issues of transportability, progress in understanding the disseminability of programs will be made.

Concluding remarks
The idea of the public sphere, propounded by Habermas (1989), called for a rationalization of power through democratically driven and mutually constructed discourse. When such a public sphere is created, one can arrive at a "rationally-motivated but not a peremptory consensus" (p. 142). Public concern about the problems of youth violence offer an unprecedented opportunity to galvanize groups of citizens who otherwise might not speak to one another — educators, scientists, policymakers, neighborhood and business leaders, church officials, family advocates — and to mobilize the efforts of all of these groups to reconstruct their communities. The public sphere can be a powerful force for change.

Author's Note
The opinions and assertions contained in this paper are the private views of the author and are not to be construed as official or as reflecting the views of the Department of Health and Human Services of the National Institute of Mental Health.

References:
Burns, B. J. (1999). A call for a mental health services research agenda for youth with serious emotional disturbance. Mental Health Services Research, 1, 5-20.

Burns, B. J., Costello, E. J., Angold, A., Tweed, D., Stangl, D., Farmer, E. M. Z., & Erkanli, A. (1995). Children's mental health service use across service sectors. Health Affairs, 14, 147-159.

Clarke, G. N., Hawkins, W., Murphy, M., Sheeber, L. B., Lewinsohn, P. M., & Seeley, J. R. (1995). Targeted prevention of unipolar depressive disorder in an at-risk sample of high school adolescents: A randomized trial of a group cognitive intervention. Journal of the American Academy of Child and Adolescent Psychiatry, 34, 312-321.

Dishion, T. J., McCord, J., & Poulin, F. (1999). When interventions harm: Peer groups and problem behavior. American Psychologist, 54, 755-764.

Gould, S. J. (1981). The mismeasure of man. New York: Norton.

Habermas, J. (1989). The public sphere. In S. E. Bonner & D. M. Kellner (Eds.). Critical theory and society: A reader (pp. 136-142). New York: Routledge.

National Institutes of Health (NIH). (1999, October 28-29). Expert Panel on Youth Violence Intervention Research.

Plotz, D. (1999, September 20). Slate Magazine.

Richters, J. E. (1997). The Hubble hypothesis and the developmentalist's dilemma. Development and Psychopathology, 9, 193-230.

Richters, J. E., & Cicchetti, D. (1993). Mark Twain meets DSM-III-R: Conduct disorder, development, and the concept of harmful dysfunction. Development and Psychopathology, 5, 5-29.

This article was written by the author as part of her responsibilities as federal government employee and is therefore in the public domain.