Handling Aggression and Self-Injury in Children with Autism: ABA Techniques for Parents

Aggression and self-injury are among the most challenging behaviors parents of children with autism may face. These behaviors can be distressing, unpredictable, and even dangerous. While they may appear sudden or without cause, they often serve a purpose for the child—such as escaping a demand, gaining access to something desirable, or expressing frustration when communication is difficult.

Applied Behavior Analysis (ABA) provides evidence-based strategies to reduce these behaviors by addressing their root causes and teaching safer, more appropriate alternatives. This article explains what drives aggression and self-injury in children with autism, and how parents can use ABA principles to intervene effectively and compassionately.

Understanding the Behavior: Why Does It Happen?

Aggressive behaviors (like hitting, biting, or throwing objects) and self-injurious behaviors (SIBs) such as head banging, hand biting, or scratching, often emerge as a way for a child to communicate or cope. Common reasons include:

Escape or avoidance: The child may want to avoid a non-preferred activity or demand.
Access to tangibles: They may be trying to get a desired object or activity.
Attention seeking: Sometimes these behaviors bring immediate responses from caregivers.
Sensory input: For some, the behavior provides internal stimulation or relieves discomfort.

A professional can conduct a Functional Behavior Assessment (FBA) to determine the purpose—or function—of the behavior. Understanding the “why” is the first step to creating an effective intervention plan.

What Parents Can Do: ABA-Based Strategies That Help

ABA focuses on changing behavior by modifying the environment and teaching replacement behaviors. Here are research-backed techniques parents can use, many of which are guided by Board Certified Behavior Analysts (BCBAs) when available:

Track the Behavior – Before you can effectively intervene, start collecting data. This ABC (Antecedent-Behavior-Consequence) data can reveal patterns, such as specific triggers or rewards that may be reinforcing the behavior. Note:
- What happened before the behavior (the antecedent)
- What the behavior looked like
- What happened after the behavior (the consequence)
Modify the Environment – If you notice aggression or self-injury tends to happen in specific situations, you can make proactive changes:
- Break tasks into smaller steps
- Provide choices to increase autonomy
- Use visual supports to reduce anxiety and clarify expectations
- Reduce sensory overload (e.g., minimize noise, provide breaks, use headphones)
Teach Replacement Behaviors – A core goal in ABA is to teach a safer, more effective behavior that meets the same need as the challenging one. The key is to reinforce the new behavior every time, so the child learns it’s more effective. For example:
- Instead of hitting to escape a task, teach the child to request a break with a card or gesture
- Instead of self-harming to get attention, teach the child to tap a caregiver or use a communication device
Use Differential Reinforcement – This means providing attention, praise, or access to rewards only when the child uses positive behaviors. For example:
- If your child scratches when frustrated, don’t react strongly in the moment. Later, praise or reward them when they use a coping strategy like deep breathing or squeezing a fidget.

There are several types of differential reinforcement. A BCBA can help you select the right one, such as DRA (alternative), DRO (other), or DRI (incompatible behavior). Learn more from this Differential Reinforcement Info Sheet (PDF)

Establish Clear Routines and Expectations – Children with autism often thrive on structure. This predictability reduces anxiety and makes the environment feel safer. Use:
- Visual schedules
- “First-then” boards
- Timers or countdowns before transitions
Reinforce Calm and Safe Behavior – Catch your child being good. Make the reinforcement immediate, specific, and meaningful to the child. Reinforce when they:
- Transition calmly
- Use communication instead of aggression
- Self-regulate (e.g., take a break, use a calming strategy)
Prepare for Challenging Situations – Gradual exposure and desensitization may be helpful, especially when combined with positive reinforcement. If you anticipate that something may trigger aggression or SIB, prepare with these tools:
- Social stories about the upcoming event
- Pre-teaching coping strategies
- Practicing with role-play
Ensure Safety – Have a crisis plan in place, especially for severe or escalating behaviors. In these cases, professional guidance is essential. During episodes of self-injury or aggression:
- Stay calm and avoid escalating the situation
- Gently block or redirect dangerous actions if needed
- Keep yourself and others safe without reinforcing the behavior

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When to Seek Professional Help

While parents can implement many ABA strategies at home, chronic or severe aggression and self-injury require guidance from qualified professionals. A Board Certified Behavior Analyst (BCBA) can:

Conduct a functional behavior assessment (FBA)
Develop a personalized behavior intervention plan (BIP)
Train family members to implement strategies safely and consistently

Collaboration with speech therapists, occupational therapists, or pediatricians may also be beneficial.

Final Thoughts

Aggression and self-injury in autism are not signs of a child being “bad” or “defiant.” They are communication attempts, sensory responses, or ways of coping with overwhelming situations. With the right strategies in place, these behaviors can be reduced—and often replaced—with healthier, more functional skills.

By applying ABA principles at home—like tracking behavior, reinforcing communication, and preparing proactively—you can help your child feel more understood, safe, and successful.