Operant conditioning: WACE Year 12 Psychology Unit 3
“Operant conditioning: the three-phase model (antecedent, behaviour, consequence); reinforcement (positive and negative reinforcers); punishment (positive and negative punishers); schedules of reinforcement (fixed, variable, interval and ratio); study: Law of effect (Thorndike, 1898); study: Skinner box (Skinner, 1948)”
Operant conditioning is learning in which a voluntary behaviour becomes more or less likely because of its consequence. The three-phase model is antecedent, behaviour, consequence. Reinforcement (positive or negative) increases a behaviour; punishment (positive or negative) decreases it. Schedules of reinforcement can be fixed or variable, and based on ratio (number of responses) or interval (time). The designated studies are Thorndike's law of effect (1898) and the Skinner box (Skinner, 1948).
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What this dot point is asking
Expect to classify consequences in a scenario, apply the three-phase model, predict the effect of a schedule, and give the aim, method, findings, contribution and limitations of both studies.
The three-phase model
- Antecedent (A): the stimulus or situation that comes before the behaviour and signals that a consequence is likely (a green light on the machine, a teacher asking a question).
- Behaviour (B): the voluntary response (pressing the lever, putting up a hand).
- Consequence (C): what follows the behaviour and changes how likely it is to happen again (food, praise, a fine).
Reinforcement and punishment
| Stimulus added (positive) | Stimulus removed (negative) | |
|---|---|---|
| Behaviour increases (reinforcement) | Positive reinforcement: praise for answering | Negative reinforcement: the seatbelt alarm stops when you buckle up |
| Behaviour decreases (punishment) | Positive punishment: a detention for being late | Negative punishment: phone taken away for missing curfew |
A reinforcer is any stimulus that strengthens the behaviour it follows; a punisher is any stimulus that weakens it.
Did the behaviour increase (reinforcement) or decrease (punishment)? Was a stimulus added (positive) or removed (negative)? "Negative" never means "bad", and negative reinforcement is never punishment.
Schedules of reinforcement
- Continuous reinforcement: every correct response is reinforced. Learning is fast, but extinction is also fast when reinforcement stops.
- Partial reinforcement: only some responses are reinforced. Learning is slower but more resistant to extinction. The four partial schedules are:
| Schedule | Reinforcement given | Example | Typical responding |
|---|---|---|---|
| Fixed ratio | After a set number of responses | A free coffee after every 9 purchases | High rate, short pause after each reinforcer |
| Variable ratio | After an unpredictable number of responses (an average) | Poker machines | Highest, steadiest rate; most resistant to extinction |
| Fixed interval | For the first response after a set time | A weekly test every Friday | Responding increases as the time approaches, then drops |
| Variable interval | For the first response after an unpredictable time | Checking for a text from a friend | Slow, steady rate; resistant to extinction |
Designated study: Law of effect (Thorndike, 1898)
- Aim
- Edward Thorndike wanted to find out how animals learn: through insight, or through trial and error.
- Method
- Hungry cats were placed in wooden puzzle boxes with food visible outside. The door opened only when the cat made a specific response, such as pulling a loop of string or pressing a lever. Thorndike timed how long each cat took to escape across many trials and plotted learning curves.
- Key findings
- At first cats scratched and pushed randomly and escaped by chance. Across trials, the time taken to escape fell gradually, and the useless movements dropped out. There was no sudden drop that would indicate insight.
- Contribution
- Thorndike proposed the law of effect: responses followed by a satisfying consequence become more likely to be repeated in that situation, and responses followed by discomfort become less likely. It was one of the first controlled experimental studies of animal learning and became the foundation for Skinner's operant conditioning.
- Limitations
- The idea of a "satisfying" consequence refers to an animal's inner state, which cannot be observed. Cats in a box learning a single response may not represent complex human learning. Keeping animals hungry and confined raises animal welfare questions.
Designated study: Skinner box (Skinner, 1948)
B. F. Skinner designed the operant chamber, known as the Skinner box: an enclosed box in which an animal's responses (pressing a lever or pecking a key) can be linked to consequences (a food pellet, or the removal of a mild electric current through the floor) and recorded automatically. This allowed reinforcement and punishment, and their schedules, to be controlled precisely.
The syllabus dates the study 1948, the year of Skinner's paper "'Superstition' in the pigeon":
- Aim
- To see what happens when reinforcement is delivered at regular intervals regardless of what the animal is doing.
- Method
- Eight pigeons were kept at 75 percent of their normal body weight so they were hungry. Each was placed in a box where food was delivered automatically every 15 seconds, no matter how the bird behaved.
- Key findings
- Six of the eight pigeons developed a clearly defined, repeated behaviour that had happened to occur just before food arrived, such as turning anticlockwise, thrusting the head into a corner or tossing the head. The behaviour was repeated between deliveries as if it caused the food. When food delivery stopped, the behaviour slowly extinguished.
- Contribution
- It showed that reinforcement strengthens whatever behaviour it follows, even when the behaviour does not actually cause it, which Skinner used to explain human superstitious rituals. More broadly, the Skinner box made it possible to measure operant behaviour objectively and to discover the effects of schedules of reinforcement.
- Limitations
- Pigeons in a controlled box may not generalise to human behaviour, which involves thinking and social factors. Other researchers later argued that some of the "superstitious" behaviours were normal food-seeking behaviours rather than learned responses. Food deprivation raises animal ethics considerations.
Some textbooks describe the Skinner box using Skinner's rat experiments, where rats learned to press a lever for food (positive reinforcement) or to switch off a mild electric current (negative reinforcement). Know how the box works, then use the version your school teaches for the aim, method and findings.
Four workplace examples
- A café worker is given a bonus for good customer reviews and gets more reviews: positive reinforcement (bonus added, behaviour increases).
- A driver slows down to stop a speed camera warning beeping: negative reinforcement (beeping removed, slowing down increases).
- A worker who arrives late is given extra cleaning duties and arrives late less often: positive punishment (duties added, lateness decreases).
- A worker loses a rostered shift for rudeness and is less rude: negative punishment (shift removed, rudeness decreases).
Marker's note: justify each label with both parts, added or removed and increase or decrease.
- Calling negative reinforcement punishment
- If the behaviour increases, it is reinforcement.
- Mixing up ratio and interval
- Ratio schedules count responses; interval schedules count time.
- Giving only the Skinner box apparatus
- For the designated study you also need an aim, findings, contribution and limitation.
- Confusing operant with classical conditioning
- Operant conditioning works on voluntary behaviour through consequences; classical conditioning works on reflexive responses through stimulus pairing.
Exam-style questions
Questions in the style of SCSA exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Original6 marksUsing the three-phase model of operant conditioning, explain why a Year 12 student is more likely to hand in homework on time after their teacher stops sending reminder emails to their parents once homework is submitted. Name the type of consequence involved.Show worked answer →
A 6 mark response needs each phase of the model applied (2 marks each).
- Antecedent
- The stimulus that comes before the behaviour and signals that a consequence is available: the homework deadline, and the knowledge that late homework triggers emails home.
- Behaviour
- The voluntary response: submitting the homework on time.
- Consequence
- The unpleasant reminder emails to parents stop. Removing an unpleasant stimulus that increases a behaviour is negative reinforcement, so on-time submission becomes more likely.
Marker's note: "negative" means a stimulus is removed and "reinforcement" means the behaviour increases. This is not punishment.
Original8 marksDescribe the aim, method and key findings of Thorndike's (1898) puzzle box study and explain how the law of effect contributed to Skinner's theory of operant conditioning.Show worked answer →
An 8 mark response needs aim (1 mark), method (2 marks), findings (2 marks) and contribution (3 marks).
- Aim
- To study how animals learn, and whether they solve problems through insight or through trial and error.
- Method
- Hungry cats were placed in a puzzle box with food visible outside. The door opened only when the cat performed a particular action, such as pulling a loop or pressing a lever. Thorndike recorded how long each cat took to escape over repeated trials.
- Findings
- At first the cats made many random movements and escaped by accident. Over trials, escape time fell gradually rather than suddenly, showing learning by trial and error rather than insight.
- Contribution
- Thorndike proposed the law of effect: responses followed by a satisfying consequence are strengthened and more likely to be repeated, while responses followed by discomfort are weakened. Skinner built on this, replacing the idea of "satisfaction" with observable reinforcement and punishment, and studied it systematically in the Skinner box, including the effect of different schedules of reinforcement.
Practise this
Sources & how we know this
- Psychology ATAR course Year 12 syllabus (effective from 1 January 2024) — School Curriculum and Standards Authority (SCSA)
- Skinner, B. F. (1948). 'Superstition' in the pigeon — Classics in the History of Psychology (York University) (1948)
- Psychology ATAR course: syllabus and support materials — SCSA
- Past ATAR course examinations — SCSA