Why the Function of Behavior Matters
Every behavior serves a purpose. A student who throws materials during math class may be doing so to escape a task that is too difficult. A teen who screams during transitions may be seeking sensory input or communicating anxiety. An adult who engages in self-injury may be trying to gain attention or relief from physical discomfort.
If an intervention targets the behavior without addressing the underlying function, the behavior will either persist or be replaced by a different challenging behavior that serves the same purpose. The FBA prevents this by identifying the function first.
The Four Functions of Behavior
Social Attention
The behavior occurs to gain attention from others — caregivers, peers, teachers, or staff. Even negative attention (reprimands, redirection) can reinforce this function.
Access to Tangibles
The behavior occurs to obtain a preferred item, activity, or sensory experience. The individual has learned that the behavior results in getting what they want.
Escape or Avoidance
The behavior occurs to get away from or delay an unpleasant demand, activity, person, or environment. This is one of the most common functions in school and therapy settings.
Automatic / Sensory
The behavior is internally reinforcing — it produces a sensory experience that the individual finds pleasurable or regulating, independent of social consequences.
How an FBA Is Conducted
A comprehensive FBA involves multiple data collection methods across multiple environments:
Structured interviews with the client, family members, teachers, and other caregivers to gather background information about the behavior, its history, antecedents, and consequences.
The BCBA observes the client in natural environments — home, school, community — collecting data on the antecedents (what happens before), the behavior itself, and the consequences (what happens after).
The BCBA analyzes patterns in the observation data to identify consistent relationships between antecedents, behaviors, and consequences that suggest the function.
In some cases, a controlled experimental analysis is conducted to directly test hypotheses about the function. This is the most rigorous form of FBA and is conducted by trained BCBAs in controlled conditions.
The BCBA synthesizes all data into a clear hypothesis statement: 'When [antecedent], [client] engages in [behavior] in order to [function].' This statement drives the BIP.
From FBA to Behavior Intervention Plan (BIP)
Once the function is identified, the BCBA designs a Behavior Intervention Plan (BIP) that addresses the function directly. The BIP includes antecedent modifications (changing the environment to prevent the behavior), replacement behavior teaching (giving the individual a better way to meet the same need), and consequence strategies (how to respond when the behavior does and does not occur). At Copper Valley, every BIP is individualized, data-driven, and reviewed regularly to ensure it is producing meaningful outcomes.