Post on 26-Dec-2015
transcript
The behaviourist approach
Access to HE Psychology
Learning outcome1: Show knowledge and understanding of psychological theories
4: Evaluate a range of key theories and perspectives in an assignment
Assessment criteria1.1: Identify key issues in named psychological perspectives
1.2: Explain the main characteristics of some psychological theories
1.3: Discuss the relationship between some key theories and perspectives
4.1: Show evidence in an assignment of the evaluation of theories and perspectives
Assessment criteria
By the end of this lesson you will be able to: -
1.3
1.2
4.1
Outline the assumptions of the behaviourist approach
Explain classical conditioning
Explain of operant conditioning
Evaluate the behaviourist perspective
Getting you thinking
How might you train a dog to fetch a lead?
How might you stop a bad habit such as biting nails?
Key assumptions • Our behaviour is shaped by the environment we live
in
• Behaviour is a response to something in the environment (stimulus)
• It’s unscientific to speculate about ‘internal processes’. Only ‘observable’ behaviour should be studied because it can be easily measured
• Behaviour is shaped via classical and operant conditioning
Watson “Give me a dozen healthy infants, well formed, and
my own specified world to bring them up in and I’ll
guarantee to take any one at random and train him to
become any type of specialist that I might
select – a doctor, lawyer, artist”
(Watson, 1925 cited in Gross, 2009:p69
• The behaviourist approach suggests two main processes whereby people learn from their environment through the principles of conditioning
–Classical conditioning: learning by association
–Operant conditioning: learning from the consequences of behaviour.
Classical Conditioning
• A procedure during which an animal or person learns to associate a reflex response with a new stimulus
• Watch the video of Pavlov’s experiment, and then answer the following questions:
– What was the original aim of Pavlov’s experiment?
– The dogs in Pavlov’s experiment would salivate on hearing his footsteps as he approached. How did Pavlov explain this reaction?
– http://www.youtube.com/watch?v=hhqumfpxuzI&p=7F7C4D28F621654B&playnext=1&index=1
Classical Conditioning
• Pavlov was initially interested in the dogs’ digestion and salutatory glands
• Pavlov suggested that dogs were associating the footsteps with the food because the two ‘things’ (the stimuli) had occurred together so many times.
Classical Conditioning • Pavlov then decided to further his research and
give the dogs food at the same time as ringing a bell (a neutral stimulus).
• Results showed that after several pairings, the dog salivated to the bell, even without the presence of food.
• The dogs associated the bell with food.
• Pavlov gave parts of his procedures particular names– Unconditioned: This refers to something
that is unlearned
– Conditioned: When something has been learned
• Classical conditioning can be described as ‘learning by association’. The dogs in Pavlov’s experiment learnt to associate the ringing of the bell with food.
Exercise
• Complete this classical conditioning schedule on the handout provided
Before conditioning trial begin – an unconditioned reflex
Food
Salivation
During conditioning trials
Bell + food Salivation
After conditioning Bell Salivation
(UCS) (UCR)
(NS) (UCS) (UCR)
(CS) (CR)
Extinction• Pavlov was also interested in how long this
learning would last.
• If he continued to ring the bell without giving the dog any food, after a while the dog would no longer salivate.
• A conditioned response which dies out is known as extinction.
Spontaneous recovery
• However, Pavlov found that after a period of rest (of not ringing the bell), if he suddenly rang the bell the dog would immediately salivate again. He referred to this as spontaneous recovery.
Generalisation
• Pavlov also found that, even if he changed the tone of the bell, the dog would still salivate.
• He referred to this as generalisation because the animal was widening its learned response to a similar conditioned stimulus (a new bell sound).
Discrimination • However, Pavlov worked out how to stop
generalisations. He rang a number of bells of different tones, but only presented food when a particular bell was rung.
• The dog did not salivate at hearing the other bells ring, and only salivated at the bell that had been paired with food.
• Pavlov referred to this as discrimination because the dog had learnt to narrow its response to a particular stimulus.
Poor little Albert… Watson and Raynor (1920)
At 9 months, Albert showed no fear of animals e.g. (rats, dogs and rabbits).
At 11 months, Albert was shown a white rat. A few second later, a hammer was struck against a steel bar which startled Albert. This experiment was repeated several times.
After a while, the rat alone induced fear within the child, who would cry and crawl away from the rat.
Question: what is the unconditional response in this experiment?
Answer: Albert’s response to the loud noise made by the hammer.
Question: What is the conditioned response?
Answer: Albert’s fear of the rat
http://www.youtube.com/watch?v=9hBfnXACsOI&feature=related
Operant conditioning
• Learning through reinforcement.
• If behaviour is positively reinforced, it should be repeated.
• If behaviour is punished, it should become extinct.
Activity • List some of the things parents/teachers could do
to encourage children to: -
– Tidy their bedrooms
– Help with the washing up
– Complete home work on time
BF Skinner
• Operant conditioning simply means changing behaviour by reinforcement: -
• Positive reinforcement: Behaviour is reinforced by rewards. E.g. The rat is rewarded food after pressing a lever.
• Negative reinforcement: Strengthening behaviour by removing an unpleasant experience. E.g. electric current, which causes the rat some discomfort, is removed when the rat presses a lever.
• Watch this clip from the big bang theory
• How is the young woman’s behaviour being shaped?
• http://www.youtube.com/watch?v=euINCrDbbD4
B.F Skinner: Operant Conditioning Skinner Box http://www.youtube.com/watch?v=PQtDTd
Dr8vs&feature=related
http://www.youtube.com/watch?v=rTND_HGrP08&feature=related
• Punishment differs from reinforcement because it does not encourage a desired behaviour; it just stops that unwanted behaviour.
• For example, we can punish a child, who has been drawing on a wall, by taking away its colouring pens.
Behaviour shaping
• Reinforcement can also be used to teach complex behaviours in animals. This is called behaviour shaping, and involves changing behaviour by breaking down a task into small steps.
• Skinner taught pigeons how to play ping pong using this technique.
Behaviour shaping: Ping-pong pigeons
• Skinner taught pigeons how to play ping pong using this technique. A pigeon will learn to play ping pong through a series of steps: -– Moving towards the ball– Touching the ball with its beak– Hitting the ball with its beak– Hitting the ball towards another pigeon
• The trainer will reinforce each of these steps by rewarding the pigeon with grain
http://www.youtube.com/watch?v=vGazyH6fQQ4
http://www.youtube.com/watch?v=I_ctJqjlrHA&feature=related
Pair activity
• Describe how behaviour shaping could be used to train a dog to fetch its lead. You will need to decided on each step of the whole procedure and the reward you will use.
• Can you think of any human behaviours that are or could be shaped by ‘behaviour shaping?
Positive reinforcement, negative reinforcement or punishment?
• A rat receives an electric shock to his brain, which creates pleasure every time he presses a bar. Before long, the rat is pressing the bar fifty times.
– Positive reinforcement
Positive reinforcement, negative reinforcement or punishment?
• Fred refuses to take out the rubbish so his mother refuses to allow him to watch his favourite TV show.
– Punishment
Positive reinforcement, negative reinforcement or punishment?
• Andrew is upset because every time he goes to school he is bullied. Andrew’s mother has noticed he complains he feels sick every morning and asks to stay home from school. His mother usually agrees.
– Negative reinforcement
Positive reinforcement, negative reinforcement or punishment?
• Tim is learning to play the trombone. His parents say that each time he successfully learns a new piece he can have some money.
– Positive reinforcement
Positive reinforcement, negative reinforcement or punishment?
• When a horn sounds hamsters jump on the wheel in their cages and begin running. They know that if they don’t jump on the wheel, a blast of cold air will blow.
– Negative reinforcement
Evaluating the behaviourist approach • Using the following points, evaluate the
behaviourist perspective: -
– What might be the advantages of laboratory experiments– What might be the practical applications of classical and
operant conditioning? – Reductionism Are complex ideas reduced to their component
parts?– Ecological Validity Can the findings be applied to real life
settings?– Extrapolation Does data from non-humans help understand
humans?
Strengths 1. Behaviourism has been very influential:
Modern psychology still relies heavily on scientific methods that were first proposed by Watson’s (1913) Behaviourist Manifesto.
2. Practical applications: Behaviourism has given rise to numerous therapeutic applications. For example:
• token economies
• aversion therapy
Weaknesses• The approach is seen as mechanistic. Human beings are
complex animals, we feel emotions, we live in complex societies etc. To see humans as functioning in a mechanistic manner is to over-simplify human behaviour.
• It excludes innate factors. We now know that genetic factors do play an enormous role in influencing human behaviour and behaviourism simply does not acknowledge this.
• It is deterministic and reductionist. The approach rejects the notion of free will, that we actively choose how to behave. Reductionist means that the approach takes complex behaviours and tries to explain them in simplistic ways (e.g. in terms of S-R units).
• Based on work with non-human animals. The approach has been criticized for making generalizations about human beings based on experiments on non-human animals