Self-Stimulatory Behaviour

Self-Stimulatory Behaviour

Most individuals with developmental delays exhibit a wide range of repetitive, stereotyped behaviours, such as rocking their bodies, shaking their heads, spinning objects, running back and forth, flapping their arms, tapping objects, smelling and licking surfaces, gazing, rolling their eyes, squinting, lining up objects, moving their fingers across textured surfaces, vocalizing, echolalia, masturbation, and a host of other behaviours. These behaviours are collectively referred to as self-stimulatory behaviour (or self-stimulation) because they provide stimulation to the person's afferent pathways. The stimulation can be olfactory, visual, auditory, kinaesthetic, or tactile in nature. Usually these behaviours are repetitive and monotonous, and they may occur daily for years. The individuals are hardly ever still; they are always doing something. Self-stimulatory behaviour and its high and repetitive rate occur with amazing similarity across persons with developmental delays and across individuals of different nationalities and ethnic compositions. My own observations of individuals with autism and pervasive developmental disorders (PDD) across Europe and the Far East reveal this similarity. Young typical children and adults evidence similar behaviours, although to a lesser degree and in transient form. In behavioural theory, such behaviours are labelled species specific. In this instance, these characteristics are common to human beings; however, one can also observe a limited range of similar behaviours such as rocking, pacing, and self-injurious behaviour in animals deprived of alternate behaviours, such as when they are held captive in a zoo. One rarely observes these behaviours in the wild where alternate behaviours are available.

Levels of Self-Stimulatory Behaviour

Various forms of self-stimulatory behaviour can be considered to fall into the following levels.

Level I: Self-stimulatory behaviours at Level I involve the body only; observation of the environment or actions upon objects in the environment result in no movement of the object or change in the object's position, size, or composition.

A. Self-stimulatory behaviours involving the eyes: Examples include repetitively blinking, squinting, rolling up one's eyes so only the whites are visible, opening one's eyes wide, staring at flickering lights or drifting dust, gazing with one's pupils positioned at the outer edges of the eyes, and gazing into space.

B. Large body movements: Examples include repetitively spinning one's body in circles, pacing, toe walking, bouncing or jumping up and down, walking repetitively around a pole, stereotyped non-directional running, body posturing as in arching one's shoulders when standing or walking, shaking one's head side to side, and masturbation.

C. Self-stimulatory behaviours involving the hands: Examples include repetitively flapping or clapping one's hands, running one's fingers along surfaces, feeling textures, rubbing one's hands or fingers together, rubbing one's face with one's hands, feeling one's hair, opening and closing one's hands, flicking one's nose or ears with one's fingers, and sticking one's finger in one's nose.

D. Behaviours involving the mouth: Examples including putting one's own hand in one's mouth, repetitively opening and closing one's mouth, clicking one's tongue, swirling saliva, licking one's lips, manipulating one's breathing pattern, blowing on one's bangs and watching the hair fall, and sucking air through one's teeth.

E. Auditory and gustatory self-stimulation: Examples include smelling and licking objects and people, making nonsense sounds, repetitively screaming, babbling, echolalia, humming, and singing.

Level II: Behaviours at Level II involve an active arrangement of the environment to provide patterning of sensory-perceptual input.

A. Inappropriate manipulation or use of objects performed to provide sensory stimulation (the behavioural topography is not characteristic of correct object use): Examples include lining up objects into rows, spinning or twirling objects, tearing objects such as pages in a book, sifting sand in front of one's eyes, sucking or mouthing objects, splashing water against the wall of a pool, swirling ashes dumped out of an ashtray, throwing pieces of paper into the air and watching them fall, rubbing tissues on one's own body, throwing objects, and using objects to tap surfaces.

B. Apparent appropriate object manipulation performed solely to provide sensory stimulation (the behavioural topography is characteristic of correct object use): In this type of self-stimulatory behaviour, the object is not used for its intended function or purpose. Examples include repeatedly switching lights on and off, opening and closing doors, turning a television on and off, pulling out and pushing in drawers, taking off and putting on shoes repetitively, swinging a tetherball around its pole and crouching to watch it go around, repetitively running up and down stairs, repetitively making dots on a piece of paper with a pencil, and collecting or hoarding objects.

C. Demand for sameness: In this type of self-stimulation, resistance is shown to the changing of object placement, interruption of behaviours, or interruption of ritual performances. Examples include insistence on using the same utensils at each meal, insistence on wearing the same clothes every day, insistence on taking the same route to school, and insistence on one's mother always wearing the same slippers.

Level III: In Level III, appropriate behaviour occurs in inappropriate contexts or for inappropriate purposes.

A. Object use that is appropriate in topography, purpose, and context, but excessive: Examples include excessive use of signs (e.g., as words, letters, numbers, phrases) in a manner devoid of their symbolic content, recalling phone numbers or birthdays, lining up objects and counting them, repetitively singing or humming songs to oneself, and saying appropriate sentences in inappropriate contexts (e.g., during the day, walking outside and saying, 'Is it dark outside?').

B. Appropriate but excessive use of objects relative to commonly accepted social norms: Examples include repetitive play requiring the appropriate use of objects, such as excessive bike riding, excessive rolling of a toy truck around the yard, excessive pretending to drive a car, and excessive assembling and reassembling of the same jigsaw puzzle.

Level IV: Behaviours at Level IV require considerable learning history. The behaviour is excessive, used in an appropriate context, and involves a meaningful use of signs.

A. Behaviour exhibited at a high intellectual level disparate WITH THE CURRENT OVERALL LEVEL OF FUNCTIONING: This type of self-stimulation is often referred to as a spliri' ter skill. Examples include memory feats, ability to reproduce in totality a long list of credits following a movie or television show, ability to reproduce correctly on the piano songs previously heard (often on the first attempt), ability to sing any note asked for and tell what note and key is being played on an instrument, ability to perform near-instant calculations of calendar dates and knowledge of what day appears on what date and year into the past or future, and unusually advanced mathematical ability (e.g., an 11-year-old who can work out in his head all the prime numbers up to 1,000 and give prime factors for all odd numbers).

B. Appropriate but excessive use of an object or performance of an activity: To be considered representative of this level, this excessive use must be coupled with the performance of other behaviours (e.g., verbal or imaginative behaviours) related to that object or activity. Together, the performance of these related behaviours demonstrates a preoccupation with that object or activity. Note that behaviours in this category differ from those in Level III in that behaviours in this category are not only excessive but are coupled with the performance of related behaviours. An example is an obsession with clocks, as when a person constantly compares clocks in different locations and checks what time it is. Also, a persistent drawing of clocks and making of clock dials, excessive talking about days and dates and what days of the week certain dates fall on, and inquiring about the birthday of each person met would be considered self-stimulatory. Obsessions with buildings (counting floors of actual buildings and pictures of buildings and stacking of objects to represent buildings in order to count their floors), elevators (talking about elevators, drawing pictures of elevators, seeking out elevators, and using toys to play elevator), vacuum cleaners (constantly talking about and imitating the function and noise of vacuum cleaners and using other objects as if they were vacuum cleaners), stairs (going up and down stairs, repetitively talking about stairs, and constructing stairs with toys), and animals (talking about animals, drawing pictures of animals, and spending long periods of time acting like a particular animal) are all likely to be self-stimulatory in nature.

What Is Known About Self-Stimulatory Behaviour

At first glance, lower levels of self-stimulatory behaviour may look particularly bizarre, perhaps pathological. On closer examination, however, all self-stimulatory behaviour shows itself to be rational and lawful just like tantrums and self-injurious behaviour. The following is a summary of what is presently known about self-stimulatory behaviour.

1. One method of reducing self-stimulatory behaviour is to increase the strength of socially appropriate behaviour. When other behaviours increase in frequency, self-stimulatory behaviours are likely to decrease. Similarly, the individual may alternate between different forms of self-stimulatory behaviours so that if one form of self-stimulatory behaviour is suppressed, it is likely that another form of self-stimulation will increase. For example, the suppression of rocking may lead to an increase in hand flapping. An ideal treatment for low-level self-stimulatory behaviour is to replace it with socially appropriate forms of self-stimulation (see Point 6).

2. It is likely that there is a biological need for sensory stimulation, that self-stimulation provides 'food' for the nervous system. For example, if an afferent system such as the visual system is blocked from input by the surgical closure of one of an animal's eyes shortly after the animal's birth, then a re-examination of the optic nerve in that eye when the animal reaches adulthood will reveal structural deterioration. Similarly, the projection area of the brain that mediates the sensory input from that optic tract will also be less developed and the animal will be effectively blind in that eye. Conversely, there is evidence that animals raised in enriched environments with large amounts of sensory stimulation show an increase in brain cell growth. In other words, self-stimulatory behaviour can be viewed as adaptive behaviour. If you are unable to teach your student alternate behaviours, let the student self-stimulate so as to help avoid damage to the nervous system.

3. When observing certain high-level forms of self-stimulatory behaviour, it may be helpful to distinguish between sensory and perceptual reinforcers. Gazing at lights (a Level I form of self-stimulation) may be controlled primarily by relatively unstructured sensory feedback from the light source. In contrast, the repetitive assembling and reassembling of jigsaw puzzles has as a consequence a specific arrangement or pattern of sensory stimuli: Circle goes with circle, square goes with square, and so on. The matching of stimuli seems to be the reinforcer that maintains the individual's behaviour. Such matching represents a patterning of sensory feedback, hence the term perceptual reinforcer. Lining up objects into neat rows is another example of arranging separate stimuli into a perceptual whole. Matching of auditory inputs, exemplified by echolalia, also illustrates a perceptual reinforcer. In describing programs for teaching match-to-sample, nonverbal imitation, and verbal imitation (Chapters 12, 13, and 22, respectively), we provide examples of the power of sensory and perceptual reinforcers in building appropriate behaviours.

4. If self-stimulatory behaviour is based on sensory perception, and if these reinforcers are primary and powerful, such as food and water rewards, then it may be difficult or impossible to reduce such behaviours. On the other hand, a teacher may use such stimulation as a reward for the student having behaved appropriately. The treatment of choice is to change lower levels of self-stimulatory behaviour to higher levels (see Point 7 below). Numerous examples of this technique are provided throughout this manual.

5. The presence of self-stimulatory behaviour decreases or blocks responsiveness to social reinforcers. This may come about because rewards derived from self-stimulation (a primary or biological reinforcer) may be stronger than social rewards the teacher can offer (secondary, symbolic, or acquired reinforcers). In an attempt to reduce the interference of competing reinforcers, the teacher may remove the objects used for self-stimulation. Or, if an individual uses her body only, the teacher may physically restrain her from doing so. As soon as the student responds correctly, the teacher may reward her by letting her self-stimulate for a brief period of time (5 to 10 seconds). If the student self-stimulates with toys, the teacher can provide access to such toys after the student engages in appropriate behaviour. In short, the teacher may use self-stimulatory behaviours constructively by reducing them when the student is given an instruction and then letting the student self-stimulate as a reward after she responds correctly to the instruction.

6. Like tantrums and self-injurious behaviours, self-stimulatory behaviours are present in typical persons as well. For example, one can observe examples of body rocking and hand flapping in typical children and adults. Even casual observations can provide evidence of high levels of self-stimulatory behaviours in typical adults. Examples of such behaviours include repetitive and stereotyped motions such as smoking, lining up of objects such as glasses and silverware on a table, neatly folding and stacking towels, matching rows of figures as done when playing slot machines, matching cards as done when playing solitaire, matching balls in holes as done in golf and basketball, marching in neat rows as done in parades, lining up and twirling as done in ballets or cheerleading performances, and clapping hands as done when applauding.

Note how society prescribes access to self-stimulatory behaviours as rewards, much as we recommend in teaching individuals with developmental delays. We self-stimulate after work, on weekends, and during vacations when we engage in playing golf, watching television, doing crossword puzzles, dancing, and a host of other high-level forms of recreational activities that involve self-stimulation. We jump up and down and repetitively clap our hands in a stereotyped manner at particularly good performances, actively reinforcing the performance with sensory rein-forcers. Anyone who has watched children at school may note classic examples of the use of self-stimulatory behaviours during recess as rewards for having sat still and complied with the teacher during the hour preceding recess.

Typical persons also often engage in self-stimulatory behaviours when there is little or nothing else to do. Excellent places to observe typical adults engaging in self-stimulatory behaviours are congested streets and freeways. While traffic is stationary or moving slowly, one may observe drivers pick their noses in a stereotyped and repetitive manner, twirl their hair, finger-play with the steering wheel, look at themselves in mirrors, smack their lips, or smile and talk to themselves. As soon as traffic moves, or the driver notes that he or she is being observed, all or most forms of low-level self-stimulation decrease and are replaced by socially appropriate behaviour. Adults rarely demonstrate low-level forms of self-stimulation when others are present, perhaps because society frowns upon engaging in such behaviours in public.

The point we are trying to make about self-stimulation is the same as the point we made in reference to tantrumous and self-injurious behaviours: Do not view such behaviour as a sign of a distorted or damaged mind. Self-stimulation is rational and intelligent, obeying the laws that regulate the behaviours of all persons. To repeat, if you do not have more appropriate behaviours to offer the individual as a substitute for self-stimulation, consider letting the individual self-stimulate to keep his nervous system from deteriorating.

7. The treatment of choice is to help individuals with developmental delays transition from lower forms of self-stimulatory behaviour to higher forms that are more socially appropriate. Socially appropriate forms of self-stimulatory behaviour may be defined as behaviours that may be enjoyed through observation or participation by more than one person. A most desirable form of self-stimulation can be observed in instances in which a performer is paid for self-stimulating, as is the case with professional sports and other entertainment. Golf and basketball players may be paid millions of dollars for matching balls into holes, and the more difficult it is to achieve this match, the more we enjoy it. We clap our hands and jump up and down to add to our appreciation, reinforcing one form of self-stimulatory behaviour (golf and basketball) with another form (clapping and jumping up and down). Many people work hard and pay to be present to watch twirling and toe-walking dancers in Tchaikovsky's Nutcracker Suite. Who is not fascinated by watching the first snowfall in the winter or the slight movements of leaves on an aspen or birch tree in the summer? A major therapeutic gain occurs when individuals with developmental delays become more like the rest of us through their transition from low-level forms of self-stimulation to higher and more socially acceptable forms of self-stimulation.