Aggression

Define the action without defining the person

“Aggressive” can become a moral judgment or an assumption about intent. A useful record describes what another observer could identify. For example: “an open or closed hand contacts another person's body with enough force to move the body or leave a visible mark.” The definition should state whether blocked attempts count, how separate contacts form one episode, and which actions are excluded.

Physical aggression, self-injury, property destruction, threats, agitation, elopement, and unsafe sexual behavior are different topographies. They may occur together and each may require a separate definition, risk route, and qualified assessment. A diagnosis, disability, communication method, or past event does not prove that aggression will occur.

Measure what matters for safety and care: people injured, injury severity, medical attention, count or rate, duration, setting, access lost, restrictive responses used, and recovery. Counts alone can hide one serious injury, while an “incident” count can combine several distinct contacts. Preserve both episode and contact definitions when each informs a decision.

Immediate response follows the person's plan

During imminent risk, follow the current individualized crisis or safety plan and the role-specific training, law, and policy that govern the setting. Create distance and remove hazards when this can be done safely. Keep communication available, reduce crowding and unnecessary stimulation, and route injuries for appropriate care. Avoid improvised restraint, seclusion, punishment, or an untrained physical procedure.

Emergency action, mandated reporting, and protection from abuse or neglect should never wait for completion of an ABA assessment. After the event, document the observable sequence, injuries, first aid or emergency response, people notified, and follow-up owner. Debrief when the person and others are ready, using accessible communication and avoiding a pressured confession.

New or changing aggression needs medical attention

The American Academy of Pediatrics' 2020 autism clinical report recommends a careful history and physical examination for medical factors that may cause or worsen behavior, including acute pain, dental injury, fracture, and gastrointestinal problems. It also describes aggression as possible communication of distress or refusal and calls for assessment of behavioral and medical factors before medication is considered for associated behavior.

Families should report sudden onset, rapid escalation, fever, injury, sleep change, eating or toileting change, seizure-like activity, medication change, pain signals, or loss of skill to the qualified medical professional. Mental-health symptoms, trauma, bullying, abuse, sensory conditions, and caregiver or staff changes may also require their own qualified reviewers. A quiet pain response or limited speech does not rule out pain.

Function cannot be read from appearance

The same action can occur under different conditions and lead to different outcomes. An episode after a demand does not prove “escape function,” and a caregiver response does not prove that attention caused it. A functional behavior assessment may use record review, interviews, direct observation, medical and communication information, and repeated measurement to develop and test hypotheses.

The BACB BCBA Test Content Outline covers operational definitions, representative measurement, descriptive assessment, functional analysis, referral, client-informed goals, contextual fit, and unwanted-effect mitigation. It is examination content for entry-level BCBAs, not a crisis protocol or authority to practice. Experimental functional analysis of severe behavior can add risk and belongs only with a qualified professional, informed consent and assent when applicable, safeguards, medical coordination, and the authority required by the setting.

The UK NICE guideline for people with learning disabilities whose behavior challenges recommends a phased, person-centered assessment covering physical and mental health, medication, communication, trauma, sensory needs, environment, relationships, direct observation, risk, and quality of life. Its population and legal context are specific. It is useful as an assessment checklist, not as universal US authority.

A plan should improve safety and quality of life

The CASP ABA Practice Guidelines public summary places ABA assessment and treatment for diagnosed autism within planning, implementation, evaluation, and standards of care. Full guideline access requires a license. This page does not attribute a specific aggression protocol to CASP.

A plan may change painful or confusing conditions, improve predictability, teach an accessible request or coping skill, train partners, reinforce a safer alternative, and define crisis response. It should identify who owns medical, clinical, operational, and emergency decisions. Food, water, bathroom use, pain care, mobility, communication, protective equipment, and necessary health care remain available regardless of behavior.

The ASHA AAC portal states that AAC users should always have access to their communication tools or devices. A person must be able to report pain, ask for help, request a pause, reject an option, and communicate assent or dissent. Removing AAC can erase information needed for safety.

For BCBA and BCaBA certificants and people who have completed an application for either credential, the BACB Ethics Code addresses competence, medical needs, assessment, consent, assent when applicable, positive reinforcement, risk minimization, client preferences, and continual evaluation. Restrictive or punishment-based procedures require additional safeguards under the Code and applicable law; their use should never be inferred from a glossary page.

A fictional assessment example

Samira is a fictional nine-year-old who uses speech and AAC. The team defines one form of aggression as a hand, foot, or held object contacting another person's body with force, plus a blocked attempt that would likely have made contact. Across ten after-school transitions, AAC is ready for 8 of 10, the agreed visual preview is delivered for 6 of 10, and an offered quiet route is available for 5 of 10. Four aggression episodes occur across three transitions, with one minor injury requiring first aid.

Samira also begins touching her jaw and sleeping poorly. The family seeks medical evaluation while the behavior analyst pauses any claim about function. After medical and behavioral review, the team changes several conditions together and teaches an accessible pause request. Across ten later transitions, one episode occurs. That before-and-after difference cannot identify a cause or the active support because medical status, access, partner response, and teaching changed together. The team continues separate safety, health, support-delivery, communication, and quality-of-life measures.