A Resource for Teachers, Clinicians, Parents, and Students by the Brain Injury Association of New York State.
Tutorial: Aggression
(See also Tutorials on Behavior Management; Anger Management)


The term “aggression” can refer to a variety of quite different – and differently motivated – social behaviors. Therefore, it has been popular to define it by listing types of aggression. Moyer’s classification system is commonly used:

  1. Predatory aggression: attack on prey by a predator.
  2. Inter-male aggression: competition between males of the same species over access to females, dominance, status, and the like, common in adolescent males.
  3. Fear-induced aggression: aggression associated with attempts to flee from a threat, such as a school assignment that seems impossible to complete successfully.
  4. Irritable aggression: aggression directed towards an available target induced by some sort of frustration, such as difficulties in academics or social life.
  5. Instrumental aggression: aggression directed towards obtaining some goal; possibly a learned response to a situation, such as getting out of the classroom by acting aggressively.
  6. Territorial aggression: defense of a fixed space against intruders.
  7. Maternal aggression: a female's aggression to protect her offspring from a threat.
  8. Paternal aggression also exists.

What runs through these types of aggression is the intention to threaten or inflict damage on another person, either as an end in itself or as a means to an end. In some cases, aggression is a learned response (e.g., instrumental aggression) to be managed with the tools of applied behavior analysis (including positive behavior supports). (See Tutorials on Behavior Management: Contingency Management; Behavior Management: Prevention Strategies; Positive Behavior Supports). In other cases, it is a natural response to difficult circumstances (e.g., fear-induced aggression; irritable aggression) to be managed with effective environmental/prevention strategies. In yet other cases, aggression can be a physiological response (e.g., predatory aggression) that might be triggered at unpredictable times in students with brain injury. Here again, careful environmental management (i.e., prevention) is crucial, possibly combined with pharmacologic intervention (i.e., medication). Prevention is crucial because of the deep biological factors underlying most episodes of aggression.

In a school context, aggression usually takes the form of (1) physical acts, like hitting and pushing (successfully completed or just attempted), directed at peers or adults, or (2) verbal acts, like threatening, cursing, taunting, and the like. Because of the need to protect children and adults alike and also the need to create a controlled environment for learning, aggression is not acceptable behavior in schools. Intervention for students who are aggressive is therefore a priority; aggression is simply not tolerated in schools and is a frequent cause of expulsion. For these reasons, it is important to understand aggression, properly identify the type of and motivation for aggression in individual cases, and implement well conceived intervention and support strategies based on an accurate understanding of the student’s aggressive behavior.


In young adults with moderate to severe TBI, aggression has been found to be a common symptom. In one large study, about 25% of the participants were identified with aggressive behavior. Aggression was more common among the younger participants. Furthermore, it was more closely tied to depression and low satisfaction with life than to the nature and severity of the injury itself. Thus environmental interventions designed to enable the student to be successful and achieve reasonable satisfaction with life at school and at home would seem to be critical for this population.

Although there are no studies specifically of aggression as an outcome of childhood TBI, clinical experience suggests that it is common. Because young children frequently manifest depression by acting out rather than withdrawing, it is likely that aggression is even more common in children than in adults. Furthermore, the high demands on cognitive, behavioral, and social functioning that school imposes increase the likelihood of both irritable aggression (because of frequent failure in school) and instrumental aggression (e.g., aggression designed to escape difficult tasks). Thus aggression can be both a reaction to overwhelming circumstances and demands, and also a tool to escape the circumstances and avoid the demands.

Finally, because the parts of the brain responsible for inhibiting inappropriate aggressive behavior – the bottom sides of the prefrontal parts of the brain – are commonly injured in TBI, the likelihood of disinhibited aggressive behavior is quite high in children with TBI. Children with damage to this part of the brain often resemble young preschoolers in the difficulty the have inhibiting impulses. It is well known that toddlers and preschoolers frequently resort to aggression to get what they want and escape what they don’t want. It is also common for older children with injury-induced impulse control problems to similarly resort to aggression.

Aggression more directly linked to the brain injury itself and brain function after the injury is also possible. In some cases, unusual stimulation of parts of the limbic system of the brain (specifically, the amygdala or hypothalamus) can cause uncontrolled aggressive responses in otherwise non-aggressive people. Similarly, temporal lobe seizures can cause uncontrolled aggressive outbursts in some cases. A careful assessment may be required to determine the possible usefulness of medications for these students.


Understanding the Problem: The first step in dealing with aggression is to understand its source and function. In the relatively unlikely event that the aggression is a direct consequence of brain injury-related events in the limbic system, then environmental management is vital. (See Tutorial on Behavior Management: Prevention Strategies.) If aggression is a learned behavior that has come to serve a purpose in the student’s life (e.g., escape from undesirable or difficult tasks), then a careful functional behavior assessment is required to identify the purpose(s) served by the behavior followed by a well conceived behavior management plan. Moreover, federal special education law mandates a clear process for functional behavior assessment and behavior plans for students with aggressive behavior. (See Individuals with Disability Education Act re-authorization for manifestation determination requirements.) If the aggression is an expression of emotional problems, then environmental management (e.g., facilitating success in school tasks and social interaction as a critical component of behavior management), possibly combined with counseling, may be needed.


Whether the aggression is a direct result of the brain injury, a response to frustration, anxiety, or depression, a learned instrumental response, or some combination of these possibilities, prevention is the critical key to effective management, especially in a public school setting..

  1. Create Positive Roles: Create positive roles and jobs for the student so that he experiences power and competence in positive ways rather than by using aggression. For example, the student can be assigned roles as the teacher’s helper, peer support person, or other special contributory job.
  2. Eliminate Triggers: Identify what environmental events or demands tend to elicit aggression and eliminate those triggers. See the five types of “child proofing” in the Tutorial, Behavior Management: Prevention Strategies.
  3. Create Well Established Routines: Create everyday routines of activity and interaction that are well understood by the students and effectively supported, so that the students are comfortable and confident of success in their lives. [See Tutorials on Instructional Routines; Organization]
  4. Provide Supports for Successful Performance: Make sure that the instructional routines are organized in such a way that the student is generally successful. (See Tutorial on Instructional Routines.) Provide meaningful praise for successful performance.
  5. Anticipate Errors and “Precorrect”: If you expect that the student will not be able to respond correctly, provide the correct response yourself in a non-punitive and non-threatening manner.
  6. Generate Positive Behavioral Momentum: Before introducing stressful or difficult tasks, make sure that the student has experienced success with less difficult or less stressful tasks. Ideally the student will have experienced sufficient success that he enters difficult tasks with a reasonable level of confidence.
  7. Ensure Clear Expectations: Ensure that instructions and expectations are clear. State them clearly, repeat them if necessary, and use concrete (e.g., graphic) organizational supports liberally. [See Tutorials on Instructional Routines; Graphic Organizers]
  8. Expect impulsive and poorly regulated behavior from time to time, especially if the student is tired or stressed, there are changes in routine, the environment is overly stimulating, or demands are high. Remain calm. Adult anxiety and agitation increase the student’s anxiety and agitation.


Seriously aggressive students may precipitate behavioral crises in which the student, peers, or adults are at risk. The following list of crisis management DOs and DON’Ts should be followed by all staff and parents.


1. Remain Calm: It is never helpful for people to respond to a behavioral crisis by going into crisis themselves, which is unfortunately a common response. Anxiety tends to be infectious. An anxious person who engages in challenging behavior often transmits anxiety to other people in the environment, thereby reducing their effectiveness and reciprocally increasing the anxiety of the person originally in crisis. Conversely, a calm person tends to interrupt the spread of anxiety. It is often better to do nothing in a behavioral crisis than to act impulsively or react in anger. Therefore, critical competencies for people working with individuals with aggressive behavior include maintaining a “stoneface” during a crisis and always appearing to know what they are doing, even when angry, frightened or completely unclear about what to do. Repeating to oneself calming words like, “This too shall pass; this too shall pass” can help one through crises. The critical message to communicate to the student in crisis is, “I’m in control; I know what to do; I’m going to help you get through this and regain your control.”

2. In the Early Stages of a Crisis, Use Redirection and Diffusion Procedures: Individuals who are escalating but not yet out of control may respond positively to redirection procedures. This is particularly true of students who are still generally confused after TBI and who tend to perseverate. They may begin to yell or act aggressively for no apparent reason, and then continue or escalate this behavior because of confusion rather than genuine anger. Abrupt redirection to a completely unrelated focus of attention may break this confused and perseverative set. However, good judgment must be exercised when using redirection. If an individual who is acting out is redirected to a highly preferred activity (e.g., eating ice cream), the redirection may have the positive immediate effect of terminating the acting-out behavior, but exacerbate the long-term problem by reinforcing that behavior (i.e., “I get it; when I threaten to hit people, I get ice cream”). Redirection should be to a neutral activity to avoid this unwanted consequence.

3. Keep Everybody Safe: In most cases, attacks on property (e.g., overturning chairs and tables; throwing objects against the wall) should not be considered matters of extreme concern, mandating physical intervention. However, people must be protected. In most cases, safety is ensured by people in the immediate environment moving away from the student in crisis. In extreme cases, that student may need to be physically restrained to prevent harm to himself or others. Physical intervention must always be guided by the principle of least intrusive intervention and by agency protocols and state regulations regarding nonaggressive physical intervention.

4. Present Yourself As a Helper: A few well chosen words like “What can I do to help?” or “Let’s get through this” sometimes help the student in crisis regain control. At least this presentation is not likely to escalate the crisis, as do confrontations, threats, arguments, and physical interventions like physical restraint.

5. Help People in Crisis Identify The Facts of the Situation and Their Feelings: Students with memory and organizational impairments often have difficulty correctly identifying the facts of the situation. They may need an adult to calmly and objectively state what has occurred. In addition, students who are cognitively immature often have difficulty identifying their feelings. For example, a toddler may react the same way when excited and unhappy, requiring parents to comfort the child by saying something like, “Honey, it’s OK. Your having fun! You got great presents. This is great -- no need for tears!”. Students with cognitive impairment after brain injury sometimes have equal difficulty identifying their feelings and may react angrily when the emotion they are experiencing is really excitement or fear. In these cases, it is important to calmly attach words to the emotion that the person is feeling at the time. For example, staff may say to a student who is beginning to threaten aggression, “This is scary. You’re a little scared, but it’s going to be OK”.

6. Speak Clearly and Simply: In an attempt to reduce the anxiety and agitation of the student in crisis, it is important to speak clearly, simply, and confidently. There should be no more than one spokesperson during a crisis. Repetition may be useful, but not if it appears to be nagging.

7. Choose Battles Wisely: Before trying to win a control battle with a student in crisis, determine (1) that the issue is worth fighting over and (2) that you can win. If you choose to engage in a battle and then lose, you seriously increase the likelihood of future battles. If you choose to engage in battles over trivial issues, you lose authority when major issues arise and you create a generally negative social environment.

8. Reset to Zero: In the event of ongoing behavioral crises with a student, it is wise to “reset to zero,” that is, to acknowledge that whatever behavior plan is in place is not working and to start again, but only after attempting to eliminate the crises with artificial means if necessary. This may entail reducing work expectations and providing unusually high levels of support. Staff or parents who are frustrated with the student may not be pleased with this proposal; however, it is generally wise to implement a new behavior plan and rebuild normal expectations for performance from a platform of no crises. Resetting to zero also entails trying to eliminate anger, resentments, and grudges so that everybody can start with a clean slate.

9. Have a Plan that All Relevant Adults Can Implement as Problems Emerge: In working with potentially aggressive students, prevention and reaction plans must be designed and taught to all relevant adults in the environment. These plans may include specific scripts to be used under specific circumstances.


In addition to the above list of positive rules of thumb for managing behavioral crises, there are problematic responses to crises that should be avoided, however natural they may seem at the time.

1. Avoid Attempting to “Teach Lessons”: After being threatened, hit, kicked, spat upon, or violated in some other way, it is tempting to say, “Look here, I’m about to teach you a lesson you’ll never forget.” Unfortunately, the history of punitive approaches to negative behavior – or aggressive approaches to aggressive behavior – is not promising. Furthermore, a time of crisis is not a time for efficient teaching and learning. Typically, if learning does occur, it is pure “limbic system learning”, that is, the memories that are retained tend to be “You are a threat to me and I need to avoid you” or “I hate this place and must escape”. This is not the sort of lesson that people with brain injury need to be taught.

2. Avoid Planting the Suggestion of a Problem Behavior: Instructions like “Do not hit me” or “Do not spit” easily have the effect of planting a suggestion in the mind of a student in crisis, or of laying down the gauntlet for a student who is angry and looking for the most damaging behavior possible on that occasion. That is, the angry student’s response to “Don’t you dare hit me!” is more likely to be “Oh, I hadn’t thought of it, but thanks for reminding me” than “Sorry, how silly of me to consider hitting you.” Suggestions can also be planted nonverbally, for example by attempting to protect things (e.g., one’s earrings, glasses, papers on the desk) that had not yet been threatened.

3. Avoid Making Threats: Threatening to impose consequences as a result of behavior during a crisis is problematic for three importantly different reasons. First, it is rarely effective. Students in crisis are rarely in a position to control their behavior by reflecting on possible consequences of that behavior. Second, the threatened consequences are frequently not administered. This is particularly true if the theat is made by one person to be carried out by another (e.g., “If you do that, you will not get to go on the outing with Mr. Smith on Friday!” or “If you do that, your father will deal with you when he gets home!”). When threats are made, but not implemented, they quickly become empty words and the authority of the person who issues the empty threats is diminished. Finally, many students with TBI cannot remember the original infraction at the time of punishment, resulting in a negative experience unrelated to the behavior that the punishment is supposed to eliminate.

4. Avoid Climbing Ladders: Often staff members and parents, particularly those who are insecure and easily threatened by loss of control, precipitate behavioral crises by engaging the student in control battles that escalate out of control. Often the first rung of the ladder is a relatively innocent exchange, such as an instruction to finish the vegetables, followed by refusal. The adult interprets the refusal as a challenge to his or her authority, and ups the ante by repeating the command firmly, possibly with a threatened consequence. The student with a history of behavior problems rises to the challenge and heightens his resistance, possibly with colorful language. The ladder continues to be climbed until the process reaches its inevitable conclusion, with both combatants falling off the ladder, locked in the grip of a behavioral crisis. “Avoid climbing ladders” is closely connected to the positive rule, “choose battles wisely.”

5. Avoid Pleading: Pleading may take the form of explicit pleas (e.g., “John, please settle down”) or more subtle pleas, often in the form of tag questions (e.g., “John, put that down right now, OK?”). In either case, pleading tacitly communicates to the student in crisis that he or she is in control of the situation, not you.

6. Avoid Confusion: Too much talk, more than one person talking, conflicting messages, and general commotion all conspire to escalate crises, rather than diffuse them. If people in the environment are not needed, they should be invited to leave the area. Teams of staff members should know in advance who will do the talking during a crisis. And the language that is used should be clear, to the point, positive, and not excessive, with adequate pause time for processing.

(See Tutorials on Errorless Learning; Positive Behavior Supports.)


In most cases, students with TBI who act aggressively do so for a combination of reasons, including their history of reinforcement, cognitive problems, self-regulatory problems, emotional frustration, and environmental triggers. Therefore, interventions must be packaged together to address all of the problems. What follows is one such package that has been used successfully with young student as well as adolescents.

  1. Positive Roles and Meaningful Jobs: Positive roles and jobs for the student are designed so that he experiences power and competence in positive ways rather than by using aggression. For example, the student can be assigned roles as the teacher’s helper, peer support person, or other special contributory job.
  2. Daily Routine: Negotiation and Choice: Daily routines are analyzed collaboratively by the instructional staff (or parents) and student. Decisions about the minimum amount of work to be accomplished and plans for achieving the goals (within limits set by general classroom routines) are made collaboratively with the student. Specific time demands (e.g., “You must finish these 10 problems in 5 minutes”) are eliminated from the routine, because they frequently evoke oppositional behavior.
  3. Behavioral Momentum: Staff ensure that the plan includes relatively easy tasks with a guaranteed high level of reinforcement before difficult work is introduced, and if possible, a student-preferred activity precedes every mandated activity.
  4. Reduction of Errors: In addition to eliminating time demands and negotiating amount of work to be completed, instructional staff and parents are trained to provide sufficient modeling and assistance so that the students experience few errors (which tend to evoke negative behavior and interfere with learning).
  5. Escape Communication: Because functional behavior assessments often indicate that aggressive behavior serves to communicate a need to escape a task or place, students are taught positive communication alternatives as replacement behaviors (e.g., “I need a break”). Staff and parents are trained to encourage these alternatives at natural transition times and when the students begin to appear anxious or upset, and to reward the students’ use of positive escape communication. (See Tutorial on Teaching Positive Communication alternatives to Negative Behavior.)
  6. Adult Communication Style: Instructional assistants and parents are trained to (1) increase their frequency of supportive and reinforcing interactions with the students, (2) anticipate students’ difficulties and offer assistance or model escape utterances, and (3) avoid “nagging” (as perceived by the students). To establish a positive style, specific scripts may be necessary for adults in their interaction with students with challenging behavior.
  7. Graphic Advance Organizers: Because of significant organizational impairment, students are provided with photograph cues or printed outlines or other visual guides. Staff and parents work with the students to choose the content of the photographs or other organizers, which could include the student engaged in the activity with or without staff, critical materials, important places, and the like. (See Tutorial on Organization.)
  8. Goal-Obstacle-Plan-Do-Review Routine: The students are given a graphic “map” that represents the general sequence of activities from an self-regulation/executive function perspective: Goal (i.e., “What are you trying to accomplish?”); Identification of difficulty level or obstacle (i.e., “Is this going to be hard or easy?”); Plan: (i.e., “How do you plan to get this done? What do you need? What are the steps? How long will this take?); Do; Review (i.e., “What were you trying to accomplish? How’d it work out? What worked for you? What didn’t work? What was easy? difficult?”). These interactions with staff are brief and collaborative (versus a performance-oriented quiz). (See Tutorial on Self-Regulation Routines.)
  9. Consequence Procedures: The antecedent control procedures described above generally result in the students’ successful performance (which is intrinsically reinforcing for the student) as well as praise from staff or parents. When the students engage in targeted negative behaviors, staff and parents respond with a verbal prompt (“You’re not ready to ...”) and remove the activity materials. Students are also reminded of the supports available to them to ensure successful completion of the task (on the assumption that their escape communication is motivated by anxiety about their ability to be successful). Staff or parents then wait until the student is ready, at which time they return to the activity they were working on at the time of the difficulty. Additional consequence strategies may not be necessary.

Procedures used in anger management may also be relevant for students who are aggressive. See the Tutorial on Anger Management for details. These include:

Anger Management Procedures Used By the Student

  1. Learning to be assertive versus aggressive
  2. Self-monitoring
  3. Self-calming
  4. Self-relaxation
  5. Joining sports teams, clubs, and the like
  6. Learning that one can only control oneself

Anger Management Procedures Used by Adults in Authority

  1. Removing Clear Provocation for Anger
  2. Using Calm Times Wisely
  3. Facilitating a Self-Concept Associated with Effective Anger Management

Written by Mark Ylvisaker, Ph.D. with the assistance of Mary Hibbard, Ph.D. and Timothy Feeney, Ph.D.

A program of the Brain Injury Association of New York State, and funded by the Developmental Disabilities Planning Council.

Copyright 2006, by
The Brain Injury Association of New York State
10 Colvin Avenue, Albany, NY 12206 - Phone: (518) 459-7911 - Fax: (518) 482-5285

.Designed and Powered by Camelot Media Group.