Introduction to the Special Issue

According to Rapp and Vollmer (2005), stereotypy is operant behavior that involves repetitious and invariant motor movements that persist in the absence of social consequences. Lanovaz and Sladeczek (2012) extended this definition to include “any repetitive sounds or words produced by an individual’s vocal apparatus that are maintained by nonsocial reinforcement” (p. 148). Although stereotypy is a defining behavioral feature of autism spectrum disorders, stereotypic behavior may also be emitted by children and adults with intellectual disabilities. Progress in the assessment and treatment of stereotypy is evident in the behavior-analytic literature; however, research on procedures for assessing and treating social reinforced behavior (e.g., attention-maintained behavior) is clearly more extensive. As a result, practitioners’ assessment of repetitive behavior may be limited to demonstrating the persistence of the behavior in the absence of social consequences (e.g., Querim et al., 2013) and, at times, their options for treating stereotypy may be limited to either noncontingent reinforcement or mild punishment procedures (e.g., response interruption and redirection). Given these relatively limited options for practitioners, additional research on both assessment and intervention procedures is clearly warranted.

As a guideline for this special issue, we sought manuscripts that represented unique contributions to the literature in terms of assessment or treatment, and the results of which were immediately applicable to practitioners. As such, the primary purpose for this special issue was to expand assessment and treatment options for practitioners; however, we also hope that these studies will offer new avenues for future research on stereotypy. The studies presented in this special issue move the field forward by highlighting limitations of current assessment technology for repetitive behavior and offering practitioners additional procedures to overcome some of those limitations. In part, some of these studies blur the lines between evaluating (a) the function of repetitive behavior and (b) the effects of interventions on repetitive behavior. Consistent with the structural and functional definition of stereotypy (Rapp & Vollmer, 2005), each of the five studies in this special issue demonstrated the persistence of the target response form in the absence of social consequences. Subsequently, four of the studies used unique analyses of motivating operations (Laraway, Snycerski, Michael, & Poling, 2003), and all five studies conducted thorough treatment evaluations using single-subject experimental designs. Moreover, four of the studies provide empirical support for specific interventions to decrease stereotypy, whereas one study provides clear evidence of an ineffective intervention.

Chok and Koesler (2014) introduced procedures for distinguishing repetitive behaviors that are categorized as stereotypy from repetitive behaviors that are categorized as obsessive compulsive. That is, the authors examined internal (i.e., change in heart rate) and external (i.e., indices of happiness) behavioral events that may be indicative of automatic positive reinforcement and automatic negative reinforcement functions, respectively. Subsequently, they provide some evidence of differential treatment effects based on the function of repetitive behavior for two individuals diagnosed with autism and intellectual disability. The Chok and Koesler study is among the first to extend functional analysis methodology for automatically reinforced behavior by using measures of physiology.

Rispoli and colleagues (2014) evaluated the effects of providing pre-session access to stereotypy as an intervention for decreasing later engagement in stereotypy while increasing engagement in group activities for three children who were diagnosed with autism. The antecedent approach outlined in this study is predicated on the assumptions that (a) engagement in stereotypy generates a reinforcing stimulus product, (b) continuous access to the product of stereotypy will generate an abolishing operation (AO) for engaging in stereotypy, and (c) AOs can be determined by behavioral indicators. Although the literature on manipulating AOs for stereotypy is still in its infancy, the intervention described in this study may ultimately provide practitioners with another option for decreasing stereotypy during instructional periods by permitting engagement in stereotypy during nonstructured periods.

Enloe and Rapp (2014) evaluated the effects of providing continuous access to a form of social interaction on the vocal and motor stereotypy of three children diagnosed with autism. Specifically, the authors endeavored to evaluate the extent to which a relatively simple and typical interaction between a trainer and a child with autism decreases the former’s engagement in one or more forms of stereotypy. This study is potentially unique, because there is limited evidence in the literature for using attention or other social interaction to treat automatically reinforced behavior such as stereotypy. In addition, the study illustrates issues that practitioners encounter when treating multiple forms of stereotypy.

Watkins and Sparling (2014) evaluated the extent to which wearing an inflatable vest decreased three participants’ engagement in either motor or vocal stereotypy. Given the conclusions recently provided by Lang et al. (2012) about the unclear or lack of effects of sensory integration therapies for individuals with autism, the findings from the Watkins and Sparling study are probably not surprising. Nevertheless, this study provides practitioners with a model for using single-subject experimental designs to directly evaluate the effects of unproven or novel interventions for stereotypy and related behavior problems (Bulkeley, Bundy, Roberts, & Einfeld, 2013; Schreck & Miller, 2010).

The final study by Zawoyski, Bosch, Vollmer, and Walker (2014) evaluated the effects of two variations of an intervention, which is commonly used to decrease vocal and motor stereotypy, on automatically reinforced repetitive behavior displayed by three typically developing children. Specifically, the authors evaluated the extent to which structurally matched and unmatched preferred stimuli decreased each participant’s engagement in automatically reinforced fingernail biting, which shares structural and functional properties with motor stereotypy. The authors conclude with a thoughtful conceptualization of the effects of matched and unmatched stimuli for decreasing repetitive behavior that occurs during specific environmental conditions.

In sum, each of these fives studies makes a unique contribution to the research literature on the assessment and treatment of stereotypy and other related behavior. The results may be used by practitioners to improve their practices when assessing and treating stereotypy. The studies presented in the special issue may also encourage other researchers to further examine how to improve clinical practices. Ultimately, we hope that these efforts will benefit individuals who engage in stereotypy and related behavior by reducing the impact of these behaviors on their quality of life.