Behavior Series

Social & Environmental Influences on Aggression

This module will:

  • Help you understand how challenging behaviors may develop
  • Give an overview of what a Functional Behavior Assessment is and how to conduct one 
  • Use the Functional Behavior Assessment to identify events that trigger or set off the challenging behavior and the reasons it may continue to occur 

To begin

  1. Click the titles of the sections below to expand and complete each section.
  2. A transcript of the module is available. Use it to read instead of watch the videos or to follow along.

Aggressive behavior in individuals with Angelman syndrome can be separated into two categories:

1. Physical aggression toward people 

  • Hitting
  • Kicking
  • Scratching
  • Pinching
  • Biting
  • Hair pulling
  • Grabbing

Sometimes, an acceptable behavior can turn into an aggressive behavior. For instance, hugging someone can turn into hair pulling or grabbing.

2. Aggression toward the environment: 

  • Throwing or breaking objects
  • Ripping, shredding or pulling apart objects

Challenging behavior such as aggression has been reported in less than 10% to as many as 100% of individuals with AS.  A major reason for this variability is different methods have been used to study aggressive behavior.

Reviews of case studies in the published literature have yielded low estimates, since many of these studies focus on the genetic rather than behavioral aspects of AS. Studies that are designed to look at behavioral issues tend to provide higher estimates, perhaps because many of the parents and caregivers who choose to participate in these studies are motivated to do so because they are already concerned about challenging behavior. More information is needed about the “true” prevalence of aggressive behavior in individuals with AS. Information is also needed about different aspects of aggressive behavior (what types of aggression occur, whether it improves or gets worse over time) as well as the impact of different interventions (behavioral approaches, medication) on aggressive behavior.

Certain factors are known to place individuals with intellectual disabilities (including those with AS) at risk for developing challenging behavior, including aggressive behavior.

  • Being nonverbal
  • Having mobility problems
  • Having severe cognitive impairment
  • Having seizure disorder

Many of these risk factors are in fact primary characteristics of AS.

There is no evidence of a direct link between the genetic defect that causes AS (UBE3A deficiency) and aggressive behavior. There is also no evidence that aggressive behavior is related to an individual’s specific genotype (deletion positive, gene mutation, uniparental paternal disomy or imprinting center defect). However, UBE3A deficiency does result in conditions, impairments and specific behavioral features that may increase the risk for individuals with AS to develop aggressive behavior. Furthermore, since behavior occurs within a broader context, social and environmental factors can modify (increase or decrease) the expression of aggression and the impact that it has on the individual’s life. Rather than being caused by one or the other, it is likely that both biological and environmental factors interact to influence how aggressive behavior develops and continues in individuals with AS.

At the present time, we can’t change the genetic defect that causes AS. However, we can try to decrease the risk that aggressive behavior will develop and continue over time by the following. First, we can try to reduce the impact of underlying conditions and impairments that can lead to behavior problems by optimizing the individual’s physical and emotional health and potential for learning. Second, we can try to replace aggressive behavior with new skills that will increase the individual’s personal and social competence, so that aggression is no longer “necessary.” Third, we can try to remove the inadvertent rewards or “pay off” for aggressive behavior to stop it from occurring and provide rewards for appropriate behavior instead. More complete information about these issues is provided in other modules.

Functional Behavior Assessment

Now that you understand aggression a little bit more, here is an introduction to completing a Functional Behavior Assessment followed by step-by-step instructions. 

Functional Behavior Assessment

Functional assessment is a process that leads to a better understanding of:

  1. The factors that make the behavior more or less likely to occur (“setting events”)
  2. The circumstances that directly set off the behavior (“antecedents”)
  3. The events that maintain the behavior (“consequences”)
  4. The reason (“function”) for the aggressive behavior.

A functional assessment can help to explain why the behavior is occurring. After this is complete, a behavior support plan is needed to outline what to do about the behavior. A behavior support plan specifies in detail what needs to be done to decrease the individual’s aggressive behavior and increase more socially acceptable behavior to take its place.

Step by Step Instructions to Complete a Functional Assessment


The starting point for doing a behavior assessment is to select the problem behavior you want to change and define it in clear, observable terms.  This is important in order for everyone to be able to recognize the behavior when it occurs.  

Be as specific as possible. Pulling hair, scratching or biting are specific forms of aggression and can be defined more precisely. For example, scratching can be defined as “using fingernails to scrape or dig into someone’s skin.”

In the case of Jack, Jack’s pinching is concerning because he has left bruises on the arms and legs of several of his support workers and pulled their hair very hard, to the point where their scalp is very sore. As a result, they are reluctant to ask him to do many things out of fear that he will hurt them. He is missing opportunities to participate in activities and learn new skills. If the situation does not change, Jack may become isolated from his peers and support staff. Pinching is defined as whenever Jack squeezes someone’s skin between 2 or more fingers. Hair pulling is defined as pulling someone’s hair with one or both hands.

Once the behavior is defined, it is helpful to survey the social and environmental context in which it possibly occurs.

checklist for context for problem behavior thumbnailTo help with this, download the Checklist for Identifying the Context for Problem Behavior.

Using the checklist, will help you find answers to questions like these:

  • Is the behavior more likely to occur (or less likely to occur) at particular times of the day?
  • Is it more or less likely to occur with particular people and in relation to what they are doing at the time?
  • Is the behavior more or less likely to occur during particular events, activities or routines?
  • Could it be related to how the individual is “feeling” (emotional state, physical health)?
  • Are there observable “warning signs” that precede the behavior occurring?
  • What happens after the behavior occurs?
  • What do you think the individual is trying to “say” through his or her behavior?


Summarize What you Learned about the Context of the Behavior

Summarize your findings using the Summary of Contextual Information form.

Summary thumbnail


See Completed Examples of Jack’s Assessment

See an example of a completed checklist of contextual factors.

See an example of a completed summary.

Based on the responses of Jack’s support workers, Jack’s aggression is more likely to occur:

  • when he is ill, hungry, tired or in an angry/bad mood
  • when he is with two particular support staff as well as unfamiliar support staff
  • when he is at the day program, particularly in the morning
  • when he is being changed, has to wait for meals or walk long distances
  • when support workers are paying attention to someone else, tell him to do something he dislikes or tell him that something he likes is not available or is finished
  • he is often given what he wants after behaving aggressively or something he doesn’t like is stopped or changed

In addition, he seems to be “saying” he wants something, he doesn’t want to stop what he is doing or he doesn’t want/like something when the aggression occurs.

At this point, you have selected and defined a problem behavior and have learned more about the context of when the behavior occurs. Now, it’s time to track the problem behavior over several days to a week. 

In order to gather valid information, it is necessary to observe the individual in different environments, at various times and with a variety of people.

Track the following about the problem behavior: 

  • Frequecy: how often the aggressive behavior occurs
  • Duration: how long it lasts 
  • Intensity: how severe it is 

Download the Behavior Tracking Sheet.

Tracking Thumbnail

What you can learn from tracking

Some aggressive behavior such as biting may not occur very often or last very long, but can be severe when it does occur and cause injury to others.  Other aggressive behavior such as grabbing at people may occur frequently and last longer in duration, but be milder in intensity. 

It is not uncommon for people to make general statements about aggressive behavior – for example “He seems to hit me every time I ask him to do something” or “It seems like she can’t go longer than a day without pinching someone.”  Behavioral tracking provides objective, quantifiable information rather than relying on people’s judgment or impressions which may not be accurate.  It can be reassuring to learn that aggressive behavior may occur much less frequently than first thought.  Returning to the previous examples, “I asked him to do 10 things today and he actually hit me once” or “She pinched her worker only once in the past 2 weeks.”

Paying close attention to frequency, duration and intensity of the problem behavior is an important step and will help sharpen your observational skills.  It can also help prepare you to directly record more extensive information about episodes that involve the problem behavior for the next step.


See a completed Example Based on Jack

See Jack’s completed tracking form

Jack’s support workers have tracked his aggressive behavior (pinching others and pulling hair) over a one-week period. Since they are all busy attending to the individuals in the day and residential programs, they shared the responsibility for tracking Jack’s behavior by setting up a schedule that assigned specific staff to cover specific periods of time (for instance, Support Worker A tracked Jack’s behavior from 9 – 11 am, Support Worker B from 11 am – 1
pm, and so on).

Jack’s support workers have been given an A-B-C chart to help them keep a detailed record of his pinching and hair pulling. Since their “roster” system worked so well for tracking when Jack’s behavior occurred, they decided to use this approach when recording behavioral
episodes. The table to the right shows how this information is recorded on an A-B-C chart. Jack’s support workers record what happens immediately before he pinches them or pulls their hair
(“antecedents”) as well as what they do in response to the aggression (“consequences”).
The immediate antecedent (“trigger”) for pinching was when the support worker said “Come, let’s go put the toy back” and tried to guide Jack out of the chair. The support worker responded to being pinched
by yelling and backing away from Jack; she also left him alone on the chair (“consequence”).
The worker had been sitting at the table with Jack, assisting him to do a puzzle. He walked away from
the table and went to sit in his favorite chair. The worker tried to “entice” Jack to get up from his chair
and come back to the table by showing him a toy. She asked him numerous times to get up (“Let’s go
put this on the table”). He tried to scratch her and reached out to pinch her or push her arm out of the
way a number of times but she was able to pull away. He also turned away from her.
After the worker finished recording what had happened, she was asked how Jack’s morning had gone.
She said he seemed tired when he arrived at the day program and had gone to sit in his favorite chair.
He covered his face with a blanket and went to sleep for an hour. She was able to get him to come to the
table to do a puzzle for a couple of minutes rather than let him sleep all morning in the chair.

 It is not possible to identify the function of a behavior based on information from only one incident. Information needs to be collected over a longer period of time (perhaps several days) in order to get a more thorough picture of the individual’s aggressive behavior and the circumstances that surround it. Once A-B-C information has been gathered, it can be reviewed to identify patterns and generate ideas (“hypotheses”) about the function of the aggressive behavior. 
People may have a variety of opinions about why the aggressive behavior occurs, but it is always better
to collect systematic information to see if their opinions are supported by facts.

Information from the A-B-C form can be used to summarize a behavioral episode.

When the worker was asked her opinion about what was Jack trying to “say” at the time he pinched her,
she thought he was saying “Leave me alone, I want to stay in the chair.” In this situation, the “function”
of Jack’s behavior may have been to continue with a preferred activity (sitting in the chair).

Once Jack’s support workers finished with the functional assessment, they tried to summarize the information they had gathered. They observed 10 episodes (or instances) of pinching and hair pulling during a one-week observation period. On 6 occasions (60% of the time), the behavior was preceded by a support worker stopping something
that Jack enjoyed. On 2 other occasions (20% of the time), the behavior was preceded by a support
worker telling Jack he couldn’t have something he wanted. All together, there was an 80% chance that
Jack would pinch support workers or pull their hair if his access to a preferred item or activity was
restricted or prevented. On 7 occasions (70% of the time), the behavior resulted in Jack being given
something he liked or being permitted to continue what he was doing. Based on the outcome of the
functional assessment, the function of Jack’s aggression (pinching and hair pulling) was hypothesized to gain or maintain access to something he wanted.

With this information in hand, Jack’s support staff were to develop the summary statement.


Frequently Asked Questions

Q: Why is it important to track behavior?

It is important to track behavior in order to obtain accurate information about what is happening, rather than relying on people’s subjective impressions.  By tracking behavior over time, it is possible to determine whether your support plan is successful. 

Q: Why is it important to do a functional assessment?

Research has shown that behavior support plans are more likely to be successful if they are based on the results of a functional assessment.

Q: How long should I track behavior?  How much information do I need to gather?

There is no set answer to this question.  It is necessary to obtain enough information over a sufficiently long period of time to be able to identify patterns in the individual’s behavior.  If the behavior happens frequently, in many situations with many different people, it may be possible to get a good sample relatively quickly.  If the behavior occurs less often or is very unpredictable, it may take longer to get a good sample.

Case Study: Jack

“Jack” is a 27-year-old individual with Angelman syndrome (deletion positive). Six months ago, he moved from a group home where he had lived for 8 years to a new group home and day program. Staff at the new agency did not receive much information from his previous placement to help with his transition. They were told he is taking risperdal because of challenging behavior.

Jack has a seizure disorder and is taking 3 different anti-epileptic medications. He has not suffered from any grand mal seizures since moving to the new agency but does have drop seizures several times daily. Jack’s foods are pureed and his liquids need to be thickened due to a history of aspiration. He is able to use a spoon to feed himself but this can take a long time.  Jack is able to walk independently but uses a wheelchair when required to walk for longer distances. He wears ankle-foot orthotics and requires assistance on stairs.

Jack does not have a formal communication system and communicates by pointing and leading people to what he wants. He uses idiosyncratic signs, such as leaning toward another person and placing the side of his head or cheek against them to indicate acceptance (“I like you”). He has a single word approximation – “om” for home. He is able to understand routine instructions in context.

Jack has a number of interests, such as watching videos and looking at photos (they need to be laminated to prevent him from ripping them). One of his favorite activities is to sit by a window and watch people walk past outside.

Jack’s support workers used to be able to divert his attention to get him to cooperate but now he is starting to pinch and hit them and pull their hair.  This happens during activities of daily living, such as when they try to change him. He may also become aggressive when they try to stop him from getting his coat when he thinks it is time to go home. At these times, he will say “om” and gesture toward the door. He often spends all morning at the day program resting or sleeping, and will cover his head with a blanket and become aggressive toward support workers if they try to get him up for activities. He appears to target a particular female support worker who has a very animated personality

Jack’s support workers want to know how they can decrease his aggressive behavior and improve his communication and leisure skills.