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September 1, 1999
Vol. 57
No. 1

In Search of the Roots of Adolescent Aggression

No easy solutions exist to eliminate school violence, but first steps may be to understand the biological basis of aggressive adolescent behavior and to discuss it with colleagues.

We are all mystified and shocked by the recent set of high school murders committed by male students. Because a relatively small percentage of adolescent males commit a disproportionately large percentage of our society's violent acts, scientists are seeking biological explanations for this limited but destructive social pathology.
What do educators need to know about normal human development and behavior to understand abnormality? What factors can explain the aggression that our profession confronts every day? Our brain is both the cause of and the cure for aggression. We need to do whatever we can to understand the brain—and to help our students understand it, too.

Our Brain's Response Systems

An important property of our brain's sensory and perceptual systems is the ability to recognize and trigger responses to real and imagined dangers and opportunities in the natural and electronic worlds. Two systems simultaneously carry out the task.
First, we have a relatively slow, analytic, reflective (primarily cortical) system to explore the objective, factual elements of a situation, to compare them with related memories of past experience, and then to rationally respond. This system is best suited to nonthreatening situations that don't require an instant response—life's little challenges.
Second, we have a fast, conceptual, reflexive (primarily subcortical) system that identifies the dangers and opportunities in a situation and then quickly activates powerful innate or learned automatic responses if survival seems problematic. This fast, stress-driven system developed to respond to imminent predatory danger and fleeting feeding and mating opportunities. Our emotional and attentional systems are thus primed to focus quickly on loud, looming, contrasting, moving, obnoxious, or attractive elements that signal potential danger, food, or mates—and to rapidly send the information to our brain's response systems.
This reflexive response, because it enhances survival, is the default system that gets the first crack at a problem. The slower, reflective system may later intervene with a more rational and appropriate solution, but most of us go through life with a long string of regrets and apologies because of the late arrival of our brain's rational solution. Our prisons are full of inmates who now wish that they had counted to 10 before acting.
Further, the brain must make rapid reflexive responses on the basis of limited and often superficial information, and so racist, sexist, or elitist stereotyping is the unfortunate byproduct. A reflexive, immature brain (of any age) tends to stereotype—to the distress of those being ridiculed and humiliated—and immature brains are common in schools.
Many elements of the reflexive system are innate—the startle reflex of an infant, for example. However, some reflexive elements must be developed through instruction and experience. We're a dependent, social species, quite helpless at birth. Our 20-year developmental trajectory includes an extended childhood, during which parents and other adults provide an important protective barrier and instruction while these systems develop, and a less-protected adolescence, during which systems mature to adulthood. All humans must travel this adolescent road, and for almost all, that road is rocky. For a few, things go terribly awry.
Both aggressive and nonaggressive adolescents generally arrive at their respective response patterns through a childhood apprenticeship in social behavior.


From birth to age 10, our developmental focus is on learning how to be human beings—learning to move, to communicate, to master basic social skills. These often require the mastery of learned social or cultural conventions, traditions, and rituals, such as movements associated with various games, differences in spoken or written languages, and our culture's definition of good manners.
The initial development is slow and awkward, but children generally function at a rapid automatic level by age 10. Adults usually allow young children to make mistakes. We smile indulgently and offer support rather than criticism as toddlers trip and as 2-year-olds make language errors. We're there principally to protect their safety and to applaud their successes because we realize that toddling leads to walking and running and babbling leads to speaking, reading, and writing.
Similarly, children tend to closely observe and model the social behavior of their parents and other adults. School further provides them with a marvelous laboratory for social learning and exploration—from structured Magic Circles to free-flowing recess behavior. Their fellow explorers are peers from families espousing a variety of values, and everyone learns to get along. Student misbehavior can become an important part of the social curriculum, much as pain is the first step to physical healing.
The school social environment should be challenging but not threatening to children who are learning to negotiate their way through real social problems. Family and neighborhoods can enhance a student's personal and social development, but schools must work with whoever comes through the door, at whatever his or her developmental level, with whatever problems he or she has. The goal is to move children to an almost automatic expression of basic social skills.
Our current obsession with raising academic standards has led to a diminished focus on the basics of personal or social development and conflict resolution, as well as a reduction in staff trained to identify and counsel students with potentially destructive behavior. The recent violent outbreaks argue for a reexamination of such decisions. Often, socially awkward children gravitate to deviant social groups during the elementary school years.


From 10 to 20, we focus on learning how to be productive, reproductive human beings—planning for a vocation and exploring emotional commitment and sexuality. The early part of this period is particularly challenging.
  • from childhood to puberty, the onset of our reproductive capabilities;
  • from concrete to formal operations, the maturation of intelligence; and
  • from an authoritarian to a consensus morality, the maturation of our personal and social identities.
The timely adolescent maturation of our brain's frontal lobes is central to the success of all three shifts. The frontal lobes play a key role in attention, reflective thought, and problem solving. Highly interconnected with our subcortical reflexive processing systems, they can inhibit impulsive and inappropriate behavior.
We can consider the years from 10 to 20 a second childhood—the awkward beginnings in each of the three major areas of change, then the gradual movement toward confidence and competence characterized by delayed and reflective (rather than rapid and reflexive) response patterns.
Busy as adolescents often are, their lives actually slow down. They hang out, often not doing much of anything. They daydream. Music becomes central to their lives—because song slows down speech so that we can insert melody, harmony, rhythm, and volume into the emotional messages of love and hate, of commitment and alienation. The music of our adolescence helps define our identity—even though adults tend to scorn the music that their children create and embrace (my parents thought that Glenn Miller's music was sensuously destructive).
Unfortunately, adults don't often offer early adolescents the same warm indulgence and social protection that they provided a decade earlier. We appreciated their preadolescent move toward rapid, reflexive, correct responses, and now we want them to get their act together quickly, forgetting that many 40-year-olds still struggle with their sexuality and morality. We respond to the awkward adolescent explorations of sexuality, critical thinking, and identity with a tendency to deride their simplistic solutions to complex problems—and we're leery of their early romantic friendships and shifts from our family's values.
Adolescents sense this, and typically they attempt to distance themselves from the adults who offered them unconditional nurturing a decade earlier. Adolescents tend to affect clothing, adornment, and behavior styles that they know will displease adults. They seek advice and nurturing from peers, through introspection, and alas, from the Jerry Springer school of conflict resolution. Those who didn't develop effective social skills must now seek friendships from a smaller pool of peers, generally those who are similarly rejected. The socially competent will support one another because we're a cooperative, social species. But we cooperate with those in our group, and we tend to be wary of others—often expressing wariness in speech and manner. The adolescent alienation of the rejected increases.
Because puberty signals the biological capacity for adult relationships and parenthood, this parental and family distancing is developmentally important. We can't maintain our primary allegiance to our childhood family while beginning to form our own mature relationships. Unfortunately, our biological readiness for parenthood occurs a decade or so before most adolescents are culturally ready for such commitment. Many disassociate from their family in their search for a personal identity with no bonding alternative in sight. Adolescent organizations and informal social groupings fill the void for many and provide a useful vehicle for developing and rehearsing positive social skills. In a secondary school culture of cliques, however, the socially rejected become even more alienated from peers who could possibly help them. Negative alliances—such as troubled couples and adolescent gangs—are an unfortunate but psychologically understandable solution to alienation.

Adolescent Aggression

No one has found a single cause or a simple solution to aggression. Some look to nature, others to nurture, for the primary cause, but trying to sort out the relative impact of each is like trying to determine whether length or width is more important when computing area. Perhaps the best advice is to choose your parents carefully—they provide you with both your genes and your jeans. We are the product of the way we organize our genetic and environmental inputs.
Others look to technology when assessing blame—to guns and to the electronically transmitted memes that permeate our culture (see sidebar). Aggression, these folks argue, increases in young people who observe violence on TV and in films, who glorify it through music, who rehearse it in violent video games, and who have ready access to guns. But tens of millions of adolescents have access to all these things, and few commit aggressive acts. A young person's sense of normality or abnormality determines the strength of the effect.
Still others look to malfunctioning brain systems, which can cause social behavior problems. For example, many mental handicaps, from autism to schizophrenia, are associated in part with attentional-system malfunctions. The adolescents who committed recent school murders seemed obsessed by their predicament and focused on it for an extended period—but we still do not know whether their attentional systems were organically impaired.
Still others look to chemical imbalances. The neurotransmitters serotonin, dopamine, and norepinephrine play important roles in regulating behavior, and low serotonin levels have been especially linked to such aggressive behavior as fighting, arson, and suicide (Sylwester, 1997). Prescription and street drugs also affect mood and behavior.
Many consider testosterone a hormonal candidate for male aggression. By examining it and how it functions, we can began to understand the connection between folklore and scientific knowledge when it comes to adolescent aggression. Testosterone is an important steroid that promotes bone growth and muscle mass, lowers the male voice, and helps develop sexual characteristics. It also binds to brain areas that influence behavior. Both males and females have testosterone, but males have much more than females.
Male testosterone levels surge between the ages of 10 and 14 before leveling off—and they fluctuate across the day and year. The folk wisdom has long been that testosterone is the correlational culprit because male aggression tends to surge in midadolescence. Sapolsky (1997) discovered that it isn't that simple. The reality is that although all adolescent males experience adolescent testosterone elevation, not all adolescent males typically respond aggressively to threat.
Two brain structures, the amygdala and the hypothalamus, play key roles in activating our rapid reflexive and often assertive response to an imminent danger or opportunity. Elevated testosterone levels don't trigger such a response, but they can turn up the volume of an already triggered reflexive response and therefore escalate simple anger and assertiveness into physical aggression. It doesn't stop there.
The ready availability of aggressive technologies—such as guns and bombs—can further escalate the destructiveness of the aggressive reflexive response well beyond our biological capabilities. Extensive contact with electronic media, games, and friends who encourage or glamorize aggression can all help develop a predisposition for an aggressive response pattern in an already alienated, testosterone-elevated adolescent—a belief that the abnormal is normal, that ridicule deserves death.
All these causes play a role in the inappropriate escalation of aggressive behavior. The key to the appropriate response, though, is a brain with mature frontal lobes that can differentiate between, for example, ridicule and genuine physical danger—and that has developed nonaggressive strategies for dealing with social disapproval and feelings of alienation.
Perhaps the best long-term strategy for reducing adolescent aggression is to identify young children who are at risk for aggression and to place them in intervention programs that will help them develop social skills and coping strategies. The First Step to Success program, for example, begins in kindergarten (University of Oregon, 1997; Walker, 1998).
At the school and classroom levels, educators must reduce the stereotyping and ridicule that alienate children who are at risk and focus on inclusive programs that develop social skills. Recent tragic events may help quiet those who consider issues of social development and self-esteem an unnecessary intrusion into what they believe should be a strictly academic curriculum. We need to focus efforts and funds on positive programs rather than on expensive school security systems.
But as we prepare for what may be an extended debate on the causes of, and solutions to, adolescent aggression, educators face two problems: (1) The technologies that can glorify and escalate aggression are seemingly constitutionally protected; and (2) our society pushes for quick fixes to complex problems. Further, we're a politicized profession that must seek community permission for much of what we do.
But what each of us can do is create an accepting climate in our schools and classrooms. It's not a glamorous solution, but it's a first step. We can foster a school setting that helps students better understand normality and abnormality in our natural and technological worlds. We can reduce stereotyping and ridicule. We can take advantage of cooperative activities that enhance social learning. We can use misbehavior as a problem-solving opportunity whenever possible. We can downplay the media glorification of aggression and guns.
Perhaps most important, we can help students understand, master, and appropriately use the power of our brain's marvelous dual reflexive/reflective problem-solving system. Our powerful, fast reflexive system responds to imminent physical threat, and our slower reflective system rationally responds to other problems. They're both biologically important, but each has its appropriate use. Murder is not an appropriate response to ridicule, nor is ridicule an appropriate response to social incompetence, nor is social incompetence an issue of no importance to schools.

Carter, R. (1998). Mapping the mind. Berkeley, CA: University of California Press.

Dozier, R. (1998). Fear itself: The origin and nature of the powerful emotion that shapes our lives and our world. New York: St. Martin's Press.

LeDoux, J. (1996). The emotional brain. New York: Simon & Schuster.

Niehoff, D. (1999). The biology of violence: How understanding the brain, behavior, and environment can break the vicious circle of aggression. New York: Free Press.

Sapolsky, R. (1998). Why zebras don't get ulcers: An updated guide to stress, stress-related diseases, and coping. New York: Freeman.

Sylwester, R. (1998). School brains, school issues: A collection of articles. Arlington Heights, IL: Skylight Training Publishing.

Volavka, J. (1995). Neurobiology of violence. Washington, DC: American Psychiatric Press.

Walker, H., & Sylwester, R. (1991, September). Where is school along the path to prison? Educational Leadership, 49, 14-17.

Robert Sylwester has been a contributor to Educational Leadership.

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