ABC - Antecedent, Behavior and Consequence

The Antecedent precedes the behavior.
Getty Images - Pedro Blanco

ABC in Applied Behavior Analysis refers to Antecedent, Behavior and Consequence, the three building blocks of analyzing and changing challenging or difficult behaviors.  

This simple formula helps a professional write a Functional Behavioral Analysis (FBA) and is usually part of the form your state or district will provide to write your FBA and BIP. A pivotal understanding of Applied Behavior Analysis (ABA,) ABC has become accepted as best practices for evaluating challenging or difficult behavior and helps the observer and the IEP 

The Building Blocks

A:  Antecedent-the environment, the events or the behavior that precedes the Behavior of Interest, or Target Behavior. Also known as the "Setting Event," the antecedent is anything that might contribute to the behavior. It may be a request from a teacher, it might be the presence of another person or student, or even a change in the environment. 

B:  Behavior-what the student does. This is sometimes referred to as "the behavior of interest" or "target behavior. It is the behavior that you are focusing on, that is either pivotal (leads to other undesirable behavior, or contributes to other undesirable behaviors) a problem behavior that creates danger for the student or others, or a distracting behavior, that removes the child from the instructional setting or prevents other students from receiving instruction. Behavior needs to be described or defined in a way that is considered an "operational definition" that describes the topography or shape of a behavior in a way that two different observers can identify the same behavior.

C:  Consequence-outcome. Sometimes the term "consequence" is used in the context of Adlerian psychology, which correlates a child's behavior of choice with the related outcome. In the ABA lexicon, it is pivotal. It is the outcome that is reinforcing for the child, so it, in turn, reinforces the maladaptive behavior.

Is the consequence that the child is placed in time out, therefore avoiding a task? Does the parent give the child a preferred item or food, in order to stop the behavior? Obviously, the behavior had the desired effect. 

Example 1

  • Antecedent: Johnny is given a vocational bin and asked to assemble the parts.
  • Behavior: Johnny sweeps the bin with all the parts onto the floor.
  • Consequence: Johnny is taken to time out and the classroom aide picks up the pieces. Johnny has avoided the task, so the function of the behavior is avoidance.

Example 2

  • Antecedent: The teacher asks a student to come to the board to move a magnetic marker.
  • Behavior: Angelina bangs her head on the tray of her wheelchair.
  • Consequence: The teacher goes to Angelina and attempts to redirect and soothe her with a preferred item (a Pretty Pony doll.) The function of the behavior is attention since it takes the teacher's attention away from the other child.
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Your Citation
Webster, Jerry. "ABC - Antecedent, Behavior and Consequence." ThoughtCo, Jan. 7, 2018, Webster, Jerry. (2018, January 7). ABC - Antecedent, Behavior and Consequence. Retrieved from Webster, Jerry. "ABC - Antecedent, Behavior and Consequence." ThoughtCo. (accessed January 23, 2018).