Shaping Behavior With Consequences
Operant conditioning explains behavior through its consequences. Two dimensions define every consequence: whether something is ADDED or REMOVED, and whether the behavior becomes MORE or LESS likely. Positive reinforcement adds something pleasant to increase a behavior (a treat for a trick); negative reinforcement removes something unpleasant to increase a behavior (a seatbelt chime stopping once you buckle up) — note that "negative" here means removal, not "bad," a frequent point of confusion. Positive punishment adds something unpleasant to decrease a behavior (a scolding); negative punishment removes something pleasant to decrease a behavior (taking away a phone).
| Adds something | Removes something | |
|---|---|---|
| Increases behavior | Positive reinforcement | Negative reinforcement |
| Decreases behavior | Positive punishment | Negative punishment |
Complex behaviors are built gradually through shaping: reinforcing successive approximations that move closer and closer to a target behavior, rather than waiting for the full behavior to occur spontaneously. Reinforcers themselves come in two kinds: primary reinforcers are innately rewarding (food, water), while secondary (conditioned) reinforcers acquire their value through learned association (money, praise, tokens).
How OFTEN a behavior is reinforced also shapes the resulting response pattern, described by four schedules of reinforcement:
| Schedule | Pattern | Example | Response pattern |
|---|---|---|---|
| Fixed ratio | After a set number of responses | Piecework pay | High rate, brief pause after each reinforcement |
| Variable ratio | After an average, unpredictable number of responses | Slot machines | Highest, steadiest rate; very resistant to extinction |
| Fixed interval | After a set amount of time | Weekly paycheck | Slow right after reinforcement, speeding up near the next one |
| Variable interval | After an average, unpredictable amount of time | Checking a messaging app | Slow, steady rate throughout |
Common pitfall: treating "negative reinforcement" as a synonym for punishment. It is the OPPOSITE: reinforcement always makes a behavior MORE likely, whether by adding something pleasant (positive) or removing something unpleasant (negative) — punishment is what decreases behavior.
Four small cumulative-response graphs: fixed ratio shows a stair-step with flat pauses, variable ratio shows a steep smooth climb, fixed interval shows a scalloped wave.