B.4 Understanding Behavior and Contingencies

Aug 26, 2025

Overview

This lecture introduces the three-term contingency (ABC Model) in behavior analysis, explaining how antecedents, behaviors, and consequences interact and are used in interventions.

The Three-Term Contingency (ABC Model)

  • Behavior occurs in response to an environmental stimulus, followed by a consequence.
  • The three parts are: antecedent (before), behavior (observable action), and consequence (after).
  • Interventions aim to modify antecedents or consequences to influence future behaviors.
  • Antecedents are cues in the environment that trigger behaviors and can be multiple for one behavior.
  • Behaviors are observable and measurable actions taken by an individual.
  • Consequences are outcomes that follow behavior; they decide if the behavior increases or decreases.

Types of Consequences

  • Consequences can be reinforcing (increase behavior), punishing (decrease behavior), or neutral (no effect).
  • Reinforcement strengthens behavior, while punishment weakens it.
  • For an event to be a consequence, it must happen after the behavior; if before, it’s an antecedent.

Examples of ABC in Daily Life

  • Child sees candy (antecedent), screams (behavior), gets candy (consequence: reinforcement—more screaming likely in future).
  • Child asks politely (behavior), gets candy (consequence: reinforcement—more polite asking likely in future).
  • Mom’s embarrassment from screaming (antecedent), gives candy (behavior), child quiets down (consequence: negative reinforcement for mom).

Expanding the Contingency

  • Sometimes a four-term contingency is used, adding a motivating operation before the antecedent.
  • Motivating operations affect the value of the consequence and influence the behavior’s likelihood.

Practice and Observation

  • Identifying the ABCs in everyday situations helps build understanding.
  • Practice by observing pets, children, or others and labeling antecedents, behaviors, and consequences.

Key Terms & Definitions

  • Antecedent — anything in the environment that cues or triggers a behavior.
  • Behavior — the observable, measurable action performed.
  • Consequence — event following a behavior that affects its future likelihood.
  • Reinforcement — a consequence that increases the future frequency of a behavior.
  • Punishment — a consequence that decreases the future frequency of a behavior.
  • Neutral consequence — event after a behavior that has no effect on it.
  • Motivating Operation — a factor that changes the value of a consequence and affects behavior.

Action Items / Next Steps

  • Practice identifying antecedents, behaviors, and consequences in daily life with pets, children, or by watching videos.
  • Focus on accurately labeling the ABC sequence for various observed behaviors.