By Matt Harrington, BCBA · Behaviorist Book Club · April 2026 · 12 min read

Client Assent: Building Compassionate and Ethical ABA Practice

Overview & Clinical Significance

Assent is one of the most important and underappreciated concepts in applied behavior analysis. While informed consent from legal guardians is a well-established requirement in ABA practice, assent addresses something fundamentally different: the ongoing, moment-to-moment communication from the client that they are willing to participate in treatment. Assent recognizes that even individuals who cannot legally consent have the right to express their preferences about what happens to them during intervention.

The clinical significance of assent extends far beyond ethical compliance. When practitioners attend to assent, they fundamentally change the nature of the therapeutic relationship. Treatment becomes a collaborative process rather than something done to a client. This shift has measurable clinical benefits: clients who are willing participants in treatment are more likely to engage with instructional demands, less likely to exhibit treatment-interfering behavior, and more likely to maintain gains after formal intervention ends.

Tessa Divine's framework for understanding assent emphasizes that it is pivotal to compassionate behavior analysis. This language is deliberate. Compassion in ABA means recognizing that our clients are not passive recipients of behavioral technology but active agents whose preferences, comfort, and dignity must be centered in every treatment decision. Assent provides the mechanism for operationalizing this commitment.

The concept of assent is particularly important in ABA because of the populations we serve. Many of our clients are children, individuals with intellectual disabilities, or others who may not have the cognitive or linguistic capacity to provide informed consent. This vulnerability makes them more susceptible to coercive treatment practices, whether intentional or inadvertent. Without systematic attention to assent, practitioners may implement procedures that the client finds aversive, distressing, or violating without realizing it.

Assent is not a single event that occurs at the beginning of treatment. It is a dynamic, ongoing process that must be monitored throughout every session. A client may assent to one activity but withdraw assent from another. They may assent at the beginning of a session but withdraw assent as fatigue or frustration builds. Practitioners must be attuned to these shifts and prepared to respond with respect and flexibility.

The clinical implications of failing to attend to assent are significant. When clients are repeatedly subjected to procedures they find aversive without avenues for refusal, the result can be learned helplessness, increased challenging behavior, erosion of the therapeutic relationship, and long-term negative associations with treatment settings. These outcomes are antithetical to the goals of ABA and represent serious ethical failures.

Background & Context

The concept of assent has roots in biomedical ethics, where it has long been recognized that individuals who cannot provide legally valid consent still deserve to have their preferences respected. In pediatric medicine, for example, assent from the child patient is sought even when the parent provides formal consent. The application of this principle to behavior analysis has been slower to develop but has gained significant traction in recent years.

The BACB Ethics Code for Behavior Analysts (2022) addresses both consent and assent, establishing clear expectations for practitioners. Code 2.11 (Obtaining Informed Consent) requires behavior analysts to obtain informed consent from legally authorized individuals before providing services. But the Code goes further: Code 2.12 (Considering Medical Needs) and related elements establish that the client's welfare and preferences must be considered throughout treatment, not just at intake.

The distinction between consent and assent is critical. Consent is a legal process whereby a person with the authority to make decisions on behalf of the client agrees to the proposed treatment. It involves providing information about the nature, risks, and benefits of treatment and obtaining agreement. Assent, by contrast, is the client's own expression of willingness to participate. It does not carry legal weight in the same way consent does, but it carries profound ethical weight.

Assent can be communicated verbally, through statements like yes, okay, or I want to do that. For clients who do not use verbal communication, assent is expressed through nonverbal behavior: approaching the therapist or materials, remaining in the treatment area voluntarily, actively engaging with tasks, showing positive affect, and similar indicators. Equally important is the withdrawal of assent, which may be communicated through verbal refusals, crying, moving away from the therapist or materials, displaying escape-maintained behavior, becoming passive and unresponsive, or showing signs of distress.

The historical context of ABA adds urgency to this conversation. Early applications of behavior analysis sometimes involved highly restrictive and aversive procedures that were implemented without regard for the client's experience or preferences. While the field has moved significantly away from these practices, the legacy of prioritizing behavior change over client dignity remains a concern in some settings. Assent-based practice represents a deliberate corrective to this history.

The growing emphasis on neurodiversity and the voices of autistic self-advocates have also shaped the conversation around assent. Many adults who received ABA services as children have described experiences of powerlessness, coercion, and trauma. While these experiences do not characterize all ABA practice, they highlight the importance of building safeguards into treatment that center the client's autonomy and preferences. Assent is one of the most important of these safeguards.

The integration of assent into practice also aligns with the values-based practice movement in behavior analysis, which emphasizes that technical competence alone is insufficient for ethical practice. Practitioners must also demonstrate commitment to the dignity, autonomy, and wellbeing of the individuals they serve.

Clinical Implications

Incorporating assent into clinical practice requires systematic changes to how behavior analysts plan, implement, and evaluate their interventions. The implications are concrete and affect every aspect of service delivery, from session structure to data collection to treatment planning.

In skill acquisition programming, assent-based practice means offering clients choices about what to work on, when to work, and how to engage with materials. This does not mean abandoning structure or allowing clients to avoid all instructional demands. Rather, it means building choice and autonomy into the instructional context. For example, rather than presenting a predetermined sequence of trials, a practitioner might offer two or three activities and allow the client to choose the order. Rather than using a single reinforcer selected by the practitioner, the client is given ongoing access to preference assessments and the ability to change reinforcers.

In behavior reduction programming, the implications of assent are particularly important. When a client withdraws assent during a behavior reduction procedure, the practitioner faces a clinical decision: continuing the procedure may achieve the behavioral objective but at the cost of the client's dignity and the therapeutic relationship. Pausing to honor the withdrawal of assent may temporarily delay progress but preserves the client's sense of safety and agency. Assent-based practice generally prioritizes the latter, recognizing that treatment outcomes achieved through coercion are ethically problematic and often unsustainable.

Data collection systems should be adapted to capture assent-related information. This might include tracking the frequency of assent and withdrawal of assent across sessions, noting the specific contexts in which withdrawal occurs, and documenting how the practitioner responded. These data provide valuable clinical information: patterns of assent withdrawal may reveal that certain procedures are more aversive than necessary, that the client is fatigued by session length, or that specific materials or activities are not preferred.

Session structure should incorporate planned breaks, transition warnings, and natural opportunities for clients to communicate their preferences. For clients with limited communication repertoires, practitioners should actively teach assent and refusal responses. Teaching a client to say no, to use a break card, or to indicate preferences through an augmentative communication system is not a barrier to treatment. It is a treatment priority that enables all future intervention to be conducted with the client's consent.

The therapeutic relationship is transformed when assent is centered. Clients learn that their preferences matter, that their communication is respected, and that they have agency in the treatment process. This foundation of trust facilitates learning and reduces the need for restrictive procedures. When clients know they can say no and be heard, they are paradoxically more likely to say yes.

Staff training must include explicit instruction in recognizing verbal and nonverbal indicators of assent and withdrawal, responding appropriately when assent is withdrawn, and understanding the rationale for assent-based practice. Many behavior technicians enter the field without exposure to these concepts and may default to compliance-oriented practices that prioritize task completion over client autonomy.

Ethical Considerations

Assent is deeply embedded in the ethical framework governing behavior analytic practice. The Ethics Code for Behavior Analysts (2022) establishes several obligations that directly implicate assent-based practice, and practitioners who fail to attend to assent risk violating multiple ethical standards.

Code 2.01 (Providing Effective Treatment) requires that behavior analysts recommend and implement treatments that are in the best interest of the client. While this code is often interpreted in terms of evidence-based practice and clinical effectiveness, it also encompasses the client's subjective experience of treatment. Treatment that is technically effective but experienced as coercive, distressing, or dehumanizing cannot be considered truly in the client's best interest.

Code 1.06 (Being Truthful) and Code 2.11 (Obtaining Informed Consent) establish the expectation that families and clients are fully informed about treatment and have the opportunity to make decisions about their care. For clients who cannot provide informed consent, assent serves as a complementary process that ensures their preferences are heard and respected, even when legal decision-making authority rests with another person.

Code 2.14 (Selecting, Designing, and Implementing Behavior-Change Interventions) requires the use of least-restrictive procedures. Assent-based practice operationalizes this requirement by ensuring that interventions are not more aversive or restrictive than necessary and that clients have avenues for communicating when procedures are experienced as aversive. When a client consistently withdraws assent from a particular procedure, this is clinical data suggesting that a less aversive alternative should be explored.

Code 2.15 (Minimizing Risk of Behavior-Change Interventions) requires behavior analysts to minimize the risk of harm associated with their interventions. Implementing procedures without attending to the client's assent carries the risk of causing psychological harm, eroding trust, inducing learned helplessness, and creating negative associations with treatment settings. These are real harms that the ethical code obligates practitioners to prevent.

A particularly important ethical consideration involves the tension between assent and safety. There are situations where honoring a client's withdrawal of assent could result in harm, such as when the client is engaging in dangerous behavior that requires immediate intervention. In these cases, the ethical obligation to protect the client from harm takes precedence, but the response should be the minimum necessary to ensure safety, and the withdrawal of assent should still be documented and addressed in subsequent treatment planning.

The ethics of teaching assent and refusal skills deserve specific attention. Some practitioners worry that teaching clients to say no will undermine treatment progress. This concern reflects a compliance-oriented view of ABA that is increasingly at odds with the field's ethical standards. Teaching clients to communicate their preferences is not only ethically required but also clinically productive. A client who can reliably communicate no does not need to resort to challenging behavior to escape aversive situations.

Organizational ethics are relevant as well. Agencies that prioritize session hours, utilization rates, or compliance metrics may create environments where practitioners feel pressure to override client assent in order to meet productivity goals. Code 2.16 (Describing Conditions for Program Effectiveness) obligates practitioners to identify conditions that are necessary for effective programming, which includes a treatment context where assent is respected.

Assessment & Decision-Making

Implementing assent-based practice requires a structured approach to assessment and decision-making that accounts for the client's communication abilities, the treatment context, and the specific procedures being used.

The first step is to assess the client's current repertoire for communicating assent and refusal. For verbal clients, this may be straightforward: they can say yes, no, or otherwise indicate their preferences. For clients with limited verbal communication, assessment should identify existing behaviors that function as assent or refusal. These might include approaching or moving away from activities, reaching for or pushing away materials, positive or negative vocalizations, changes in body tension or posture, and facial expressions. Working closely with families and caregivers is essential, as they often have the most nuanced understanding of the client's communicative behaviors.

For clients who lack reliable means of communicating assent and refusal, teaching these responses becomes a treatment priority. This might involve teaching the use of a break card, introducing an augmentative communication device with yes and no options, establishing a simple gesture or signal for stop, or building choice-making skills that allow the client to indicate preferences. The specific modality should be selected based on the client's existing skills and the communication systems already in use.

Once assent communication is established, practitioners need clear protocols for how to respond when assent is withdrawn. These protocols should specify what the practitioner does immediately upon detecting withdrawal of assent, how long the pause or break lasts, what conditions must be met before resuming the activity, and when to modify the activity or replace it with an alternative. These protocols should be individualized based on the client's needs and the clinical context.

Decision-making about when to continue versus when to pause requires clinical judgment. A useful framework is to consider the function of the withdrawal. If the client appears to be withdrawing assent because they are experiencing genuine distress, discomfort, or fatigue, honoring the withdrawal is both ethically required and clinically sound. If the withdrawal appears to function as escape from a mildly effortful task that is within the client's ability, the response may involve providing additional support, modifying the task demand, or offering a brief break before returning to the activity.

Critically, this distinction must not be used as a justification for overriding all refusals that might be escape-maintained. Even when escape is the function, the client's communication should be honored to some degree, and the treatment plan should be modified to reduce the aversiveness of the demands. The goal is to make participation more reinforcing, not to eliminate the client's ability to refuse.

Data-based decision-making should incorporate assent data alongside traditional measures of skill acquisition and behavior reduction. If a particular program consistently generates high rates of assent withdrawal, this is a signal that the program needs modification. Trends in assent data across sessions can reveal important patterns about treatment acceptability and client wellbeing that traditional behavioral data may not capture.

What This Means for Your Practice

Implementing assent-based practice begins with a philosophical commitment to viewing your clients as active participants in their treatment rather than passive recipients. This commitment must then be translated into concrete changes in how you conduct sessions, train staff, and design treatment plans.

Start by assessing every client on your caseload for their ability to communicate assent and refusal. For those who lack reliable means of doing so, add communication goals that specifically target assent and refusal responses. These goals should be treated as foundational, because all other treatment is more ethical and more effective when the client can express their preferences.

Revise your session protocols to include structured opportunities for choice, planned breaks, and clear responses to withdrawal of assent. Develop written protocols that specify what staff should do when a client says no, cries, moves away from materials, or otherwise indicates unwillingness to participate. These protocols should be part of every client's treatment plan, not left to individual staff judgment in the moment.

Add assent data to your data collection systems. This does not need to be complicated. A simple frequency count of assent withdrawals per session, with notes on context and staff response, provides valuable clinical information. Review this data regularly alongside your other outcome measures.

Train your behavior technicians explicitly in recognizing and responding to assent. Many RBTs enter the field focused on compliance and task completion. Help them understand that honoring a client's refusal is not a failure but a sign of ethical, compassionate practice. Model assent-based practice during supervision observations and provide feedback on staff responses to assent withdrawal.

Communicate with families about assent. Help parents understand that your treatment approach respects their child's right to express preferences and that teaching their child to say no is actually a valuable clinical goal. Many families will find this approach reassuring and aligned with their values.