1. Edwin Thorndike’s “Puzzle box”

2. Thorndike’s Law of Effect Your text’s paraphrase (p. 226): The law of effect states that behaviors leading to a satisfying state of affairs are strengthened or “stamped in,” while behaviors leading to an unsatisfying or annoying state of affairs are weakened or “stamped out.” “In other words, the consequences of a behavior determine whether the behavior will be repeated.”

3. What Thorndike really said: “If a response in the presence of a stimulus is followed by a satisfying state of affairs, the association between the stimulus and the response will be strengthened; if the response is followed by an annoying state of affairs, the association will be weakened.” Note that the learned association is between a stimulus and a response. Therefore, it was called S-R Learning.

4. Why does pain hurt? Why are eating and sex fun? We clearly benefit by our ability to detect and avoid pain -- after all, pain is usually associated with damage to our body. We also benefit by our ability to detect and seek out pleasant situations, such as those that provide us with food, drink, sex, etc. Our ability to detect and react to these hedonic situations increases our fitness. Hedonism is good!

5. Remember Shepard’s Rule? Shepard’s rule implies that our reflexes and other innately disposed behavior patterns have evolved in ways that guarantee matches with environments we are likely to encounter during our lifetimes. That is, our reflexes are adaptive, and their modification through learning, no matter how mechanical the process may be, also tends to increase our fitness with the environment.

6. The law of effect may be an inevitable outcome of natural selection. Those animals in past times who were not sensitive to “positive reinforcers” or “punishers” (i.e., those aspects of the environment that promote survival) would have gone extinct. Therefore, all existing animals were selected to obey the law of effect. That is why we and other animals are hedonists!

7. Effect of Stimulus on Behavior: Punishment: Decrease Probability Reinforcement: Increase Probability Type of Contingency Positive: If Response Then Stimulus Negative: If Response Then NO Stimulus Positive Reinforcement Negative Reinforcement Stimulus: usually appetitive Stimulus: usually aversive Punishment “Punishment by Addition” “Positive Punishment” Stimulus: usually aversive Ex: Spanking, Yelling, “Cold stare” Omission “Punishment by Subtraction” “Negative Punishment” Stimulus: usually appetitive Avoidance, Escape Ex: “Thank you!” “rewards” Ex: Grounding, DRO, suspended license, response cost, timeout

8. Cumulative recorder

9. Sample cumulative records of 4 simple reinforcement schedules