B. F. Skinner

1. B. F. Skinner Radial Behaviorism

2. B.F. Skinner (1904-1990) • 1925: Hamilton College (NY): degree in English, no courses in psychology • Read about Pavlov’s and Watson’s experimental work • 1931: Ph.D. from Harvard

3. What did Skinner study? • Findings about the ways animals discover and learn things • Most actions (or behaviours) are basically learned, and can be unlearned and changed. • “Personality is the result of measuring outside forces. Thus, how we think and act can be modified by manipulating our environment.” (ABC’s of the Human Mind)

4. B. Operant Conditioning • Learning occurs through the presentation of rewards or punishments that influence voluntary behaviors.

5. Operant Conditioning • Changes in behavior is the outcome of an individual responding to occurrences in the environment (stimuli) • If the subject is correctly stimulated it will give the suitable response • When a stimulus-response pattern is reinforced (rewarded), the individual is conditioned to respond in a certain manner

6. Operant Conditioning – BF Skinner Law of effect (Thorndike) = if a behavior is followed by a better or more satisfying state of affairs, that behavior is more likely to occur again in the future. If a behavior is followed by a less satisfying state of affairs, that behavior is less likely to occur in the future.

7. Operating Conditioning Concepts Neutral operants: • responses from the environment that neither increase nor decrease the probability of a behavior being repeated. Reinforcer– anything that strengths a behavioral tendency • Positive reinforcement = getting something good • Negative reinforcement = taking away something aversive Punishment – anything that weakens a behavioral tendency • Can remove something positive (from positive to neutral) • Can give something negative (go from neutral to negative)

8. Skinner’s Work: • Skinner showed that by presenting animals (tested on pigeons and rats) or people withrewards & punishmentsyou could shape behavior. • Initially, to get a new behavior to appear & then be conditioned, you have to use shaping. • Shaping involves presenting a reinforcement for each successive approximation of a desired behavior. • E.g., if we want to shape lever pressing in rats, we would reinforce any behavior that even remotely resembles lever pressing.

9. Reinforcement-strengthens a behavior • 1. Positive Reinforcement: Strengthens a response by presenting something that is perceived as appetitive (pleasant) after a behavior is emitted. • E.g., a good grade received after studying for an exam, a food reward for pressing a lever, etc. • 2. Negative Reinforcement: strengthens a response by removing an aversive(negative) stimulus after a behavior is emitted. • E.g., people smoke more, to reduce aversive sensations associated with nicotine withdrawal.

10. Punishment: Two forms • 1. Positive Punishment - apply an aversive stimulus when an undesired behavior occurs. Must be immediate to be effective. • E.g., presenting lemon juice on a toddler’s tongue immediately after he or she bites. • 2. Negative Punishment - remove an appetitive (pleasant) stimulus when an undesired behavior occurs. • E.g., revoking a teenager’s driving privileges if they get a speeding ticket.

11. Skinner Box • Skinner created an apparatus that would present rewards to an organism (animals & humans!!) based on their behavioral responses. • He even had his daughter stay in the box for several experiments.

12. Lab Experiment: Skinner’s Box and Rats

13. Skinner’s Rats • Rats were placed in metal cages with a number of levers. • The rats first accidentally pressed the levers in the cage, causing food or water to drop into a dish. • After repeating the action, the rats saw that they could receive food and water by pressing the lever. (Learned this behaviour) • So, when the rats were rewarded they were conditioned to repeat this positive action to continue being rewarded

14. Reinforcement • Continuous Reinforcement: Every time the rat does the appropriate behavior, he gets a pellet (food). • Fixed ratio schedule: If the rat presses the pedal three times, he gets a pellet…or five times, or twenty times, or x times. There is a fixed ratio between behaviors and reinforcers. • Fixed interval schedule: If the rat presses the bar at least once during a particular period of time, say 20 seconds, he gets a pellet. But whether he presses the bar once or a hundred times within that 20 seconds, he only receives one reinforcer. • Variable ratio schedule: You change the x each time. First it takes 3 presses to get a pellet, then 10, then 4, etc. • Variable interval schedule: You keep changing the time period. First 10 seconds, then 35, then 5, then 40.

15. Skinner’s Box and Rats • http://www.youtube.com/watch?v=PQtDTdDr8vs

16. What if the rat doesn’t get any more pellets? EXTINCTION: After a few futile attempts, the rat stops the bar-pressing behaviour

17. Skinner Box &Pigeons VIDEO • Skinner conditioned the pigeon’s to peck at a particular colored disk only when a light was on the cage and thus, getting rewarded by food and water. • This is based on Skinner’s theory of Operant Conditioning- behaviours are repeated if they are rewarded, and behaviours that are punished will be avoided • Light=Primary Reinforcer • Food &Water: Secondary Reinforcer

18. Importance of Skinner:Behaviour Modification Definition: adjusting the environment to change behavior by the use of timely reinforcement (positive and negative)

19. Behaviour Modification & Skinner • Believed that people could be persuaded to show “good” behaviour if they were properly reinforced for displaying them • If they displayed bad behaviour, the reward would be withheld.

20. Behaviour Modification and The Big Bang Theory Video

21. Why is it important to the social sciences? • Knowing how people learn behaviour is a necessity to our society so that we can control and promote the good behaviour, which will benefit society as a whole. • The theory of operant-conditioning helps us to control the way humans learn behaviour and how society can be a great influence on behaviour • Helps us to understand how to improve behaviours (people with problem behaviours and criminal histories)