These answers draw in part from “Advancing the Understanding and Application of Assent in Behavior Analysis” by Anna Linnehan, PhD, BCBA-D (BehaviorLive), and extend it with peer-reviewed research from our library of 27,900+ ABA research articles. Clinical framing, BACB ethics code references, and cross-links below are synthesized by Behaviorist Book Club.
View the original presentation →Consent is a legal concept requiring the capacity to understand the nature and consequences of a proposed action, evaluate alternatives, and voluntarily agree. It is typically provided by parents or guardians for clients who lack this capacity. Assent is a behavioral concept referring to observable indicators that a client is willing to participate in an activity, regardless of their capacity for formal decision-making. A nonverbal child cannot provide consent but can demonstrate assent through approach behavior, active participation, and the absence of distress signals. Both consent and assent are ethically important, but assent provides the ongoing, moment-to-moment mechanism for honoring client preferences during treatment.
Operational definitions of assent for clients with limited communication should be based on careful observation across multiple contexts and input from caregivers who know the client well. Focus on observable behavioral indicators such as approach versus avoidance of the therapist and materials, body posture and muscle tension, facial expressions, vocalizations, and level of active participation in activities. Positive indicators might include reaching for materials, orienting toward the therapist, relaxed posture, and sustained engagement. Withdrawal indicators might include turning away, increased rigidity, pushing materials away, or engaging in escape behavior. These definitions should be individualized and reviewed as you learn more about the client.
When a client withdraws assent, your response should be guided by a predetermined protocol that accounts for safety and clinical context. In most situations, the appropriate immediate response is to pause the current demand, acknowledge the client's communication, and offer alternatives such as a break, a preferred activity, or a choice between modified demands. After assent is restored, you may return to the therapeutic activity at an appropriate pace. Document the episode and evaluate whether modifications to the approach are warranted. If withdrawal occurs frequently during a particular activity, this pattern signals that the activity may need to be restructured to better support client engagement.
This is the most challenging aspect of assent-based practice. When a client withdraws assent during treatment of dangerous behavior, you must weigh their immediate communication against the risk of harm. A useful framework is to evaluate whether the risk from continuing the intervention is greater or less than the risk from stopping it. If pausing creates an unacceptable safety risk, you may continue while implementing strategies to reduce distress and restore assent quickly. Document the rationale for any decision to continue despite withdrawal, and regularly reevaluate whether less intrusive approaches might achieve the same safety objectives. This should be a temporary measure, not a permanent feature of treatment.
The BACB Ethics Code (2022) addresses assent through several provisions. Code 2.11 establishes the right to withdraw consent and, by extension, the client's ability to communicate unwillingness. Code 2.01 requires effective treatment, which includes treatment that respects client dignity and autonomy. Code 3.01 requires acting in the client's best interest, which includes attending to their moment-to-moment experience during treatment. Code 2.15 requires minimizing risk of behavior-change interventions, which is relevant when assent conflicts with treatment procedures. Together, these codes create a framework that obligates practitioners to systematically attend to and respond to client assent.
Assent and compliance are fundamentally different concepts. Compliance refers to the client following through with a direction or demand, which may occur willingly or unwillingly. A compliant client may be cooperating because they find the activity reinforcing, or they may be cooperating because the consequences of noncompliance are aversive. Assent refers specifically to the client's willingness to participate, as evidenced by behavioral indicators of comfort and engagement. A client can be compliant without assenting if they follow instructions while displaying indicators of distress. Assent-based practice goes beyond obtaining compliance to ensuring that the client's participation is genuinely willing.
Yes, incorporating assent data into your formal data collection system provides valuable information for clinical decision-making. You can track the frequency and duration of assent withdrawal episodes per session, the activities or contexts that most commonly occasion withdrawal, the strategies used to restore assent and their effectiveness, and trends over time in the overall frequency of withdrawal. Graphing these data allows you to evaluate whether your treatment approach is becoming more or less acceptable to the client over time and to identify specific activities or procedures that may need modification. This data-based approach to assent aligns with the field's commitment to empirical decision-making.
RBT training in assent-based practices should include the specific operational definition of assent and withdrawal for each client they serve, observable examples and non-examples of assent indicators for each client, a clear response protocol for what to do when withdrawal is observed, practice scenarios with feedback on identifying and responding to assent indicators, documentation procedures for recording assent-related observations, and guidance on when to contact the supervising BCBA about assent concerns. Training should be ongoing rather than a single event, with regular checks during supervision to ensure that RBTs are accurately identifying and appropriately responding to assent indicators.
Teaching communication skills is one of the most powerful ways to support assent-based practice. When clients can request breaks, express preferences, indicate readiness, and communicate discomfort through functional communication responses, assent becomes a collaborative process rather than something inferred from nonverbal cues alone. Functional communication training that includes responses such as asking for a break, requesting a preferred activity, or saying they are ready to continue gives clients direct tools for managing their treatment experience. Prioritizing these communication targets serves both the clinical goal of skill building and the ethical goal of honoring client autonomy.
The neurodiversity movement has raised important concerns about ABA practices that prioritize compliance and normalization over client autonomy and well-being. Assent-based practice directly addresses many of these concerns by requiring practitioners to attend to the client's experience during treatment, to honor their communication of unwillingness, and to continuously evaluate whether treatment goals and methods are consistent with the client's dignity and preferences. By implementing robust assent practices, behavior analysts demonstrate that the field can be both scientifically rigorous and respectful of individual autonomy. This represents an important evolution in ABA that responds constructively to legitimate criticism.
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All behavior-analytic intervention is individualized. The information on this page is for educational purposes and does not constitute clinical advice. Treatment decisions should be informed by the best available published research, individualized assessment, and obtained with the informed consent of the client or their legal guardian. Behavior analysts are responsible for practicing within the boundaries of their competence and adhering to the BACB Ethics Code for Behavior Analysts.