Describe the mechanisms of operant conditioning; give
one example of
operant conditioning in humans (suitable examples would include the acquisition
of language), and evaluate
operant conditioning as explanations of human behaviour. |
"A person does not act upon the world, the world acts upon him." - B. F. Skinner
Try this tutorial on operant conditioning: http://www.worthpublishers.com/myers5e/content/psychsim/index.htm
Powerpoint on operant conditioning
Operant conditioning was first described by Thorndike’s (1898) ‘Law of effect’ - a behaviour resulting in a pleasant outcome tends to be repeated, whereas behaviours followed by bad consequences are not.
This came about following a number of studies involving hungry cats learning to escape from puzzle boxes and thereby achieving the reward of some food. Over successive trials the cats got faster and faster at escaping from the boxes.
 |
In
the 1930s, B. F. Skinner (1904–1990) began to change the way
psychologists think about conditioning and learning. Skinner questioned
whether the passive Pavlovian (classical) conditioning that focused on
reflexive, automatic responses should be studied at all. Instead, he
focused solely on an organism’s observable behavior and did not
consider thought processes, consciousness, brain–behavior relationships,
and the mind to be proper subject matter for psychological research.
According to Skinner,
most behaviors can be explained through operant conditioning, rather
than through Pavlov’s classical conditioning.
Skinner used the term operant conditioning because the organism operates
on the environment, with every action followed by a specific event,
or consequence. Operant conditioning, or instrumental conditioning,
is conditioning in which an increase or decrease in the probability
that a behavior will recur is affected by the delivery of reinforcement
or punishment as a consequence of the behavior. The conditioned behavior
is usually voluntary, not reflexive, as in classical conditioning. |
| Skinner performed experiments using a different type of box. This is known as the Skinner box. The animal inside the box had to perform some kind of behaviour or operant (lever pressing for rats and disc pecking for pigeons) resulting in a consequence - a positive or negative reinforcement or punishment. According to Skinner, these consequences shape and maintain the behaviours (Skinner, 1938). |  |
The mechanisms of operant conditioning are:
Positive Reinforcement : Making a behavior stronger by following the behavior with a pleasant stimulus. For example, a rat presses a lever and receives food.
Negative Reinforcement: Can be used
to escape or avoid an unpleasant stimulus. Making a behavior stronger by
taking away a negative stimulus. For example, a rat presses a lever and
turns off the electric shock.
Positive Punishment : Reducing a behavior by presenting
an unpleasant stimulus when the behavior occurs. If the rat previously
pressed the lever and received
food and now receives a
shock, the rat will learn not to press the lever.
Negative Punishment (aka extinction): Reducing a behavior
by removing a pleasant stimulus when the behavior occurs. If the rat
was previously
given food for each
lever press, but now receives food
consistently when not pressing the lever (and not when it presses the lever),
the rat will learn to stop pressing the lever. Punishments can only weaken
existing behaviours, so do not lead to the learning of new ones.
A primary reinforcer is one that fulfills a basic physical need for survival and does not depend on learning. Food, water, sleep, sex and termination of pain are examples of primary reinforcers. Fortunately, learning does not depend solely on primary reinforcers. If that were the case, people would need to be hungry, thirsty, or sex starved before they would respond at all.
Much observed human behavior occurs in response to secondary reinforcers. A secondary reinforcer is acquired or learned through association with other reinforcers. Some secondary reinforcers (money for example) can be exchanged at a later time for other reinforcers. Praise, good grades, awards, applause, attention,and signals of approval, such as a smile or a kind word, are all examples of secondary reinforcers.
Drag the correct consequence (pink) onto the blue text and then mark your answer:
A Positive reinforcers (for example, food).
B Negative reinforcers (for example, electric shock).
C Punishers (for example, electric shock).
Shaping: The animal learns a new behaviour by the reinforcement of responses that are a step closer to the desired behaviour. This is the method used to train animals. A form of shaping is used to teach people with learning difficulties to carry out tasks for themselves, for example, feeding, using the toilet, for example. This is called behaviour modification.
Superstitious Behavior: Occurs when a behavior is accidentally followed by a reward . Organism may repeat the behavior, even if the reward had other causes.
Schedules of reinforcement: Of course reinforcements in real life don’t occur every time a behaviour occurs. “Different schedules of reinforcement lead to different behavioural tendencies across time”.
Reinforcement can of course be CONTINUOUS, PARTIAL, FIXED RATIO, VARIABLE RATIO, FIXED INTERVAL and VARIABLE INTERVAL.
click here for powerpoint on schedules of reinforcement
click here for help of schedules of reinforcement
Evaluation of Operant Conditioning
Operant learning techniques work well with animals, and with some situation may apply to humans. For example, autistic children have been taught to dress themselves etc. Mentally disturbed adults have also been ‘trained’ to behave more normally. But not all learning is as a result of previously reinforced responses. Some is totally new. Some learning is accidental, some is spontaneous, and some occurs for no apparent reason at all.
Skinner and other Learning theorists have shown how child’s social skills are guided by both deliberate and unintended learning experiences in the home, peer group, school, and community. Gender identity for example can develop through reinforcers and punishers. For example Boy kicks a ball around and, other boys join in. His behaviour has been reinforced. If that same boy chooses to play with a doll, other boys will make fun of him. This will act as a punisher and decrease the playing with dolls.
Childhood growth then is significantly shaped by the efforts, intentional
or otherwise of parents, teachers, and others to socialize children in desirable
ways
Skinner argued that the child even acquires verbal language by selective
reinforcement. Pre-linguistic vocalizations are innate but the parent reinforces
such expressions as ‘mama’ or ‘dada’ through correcting
them and rewarding them through imitation, a smile or a hug. However, adults
don’t
always reinforce young children so how do children use the correct grammar.
Chomsky thought humans acquire language through their Language acquisition
device (LAD).
Operant conditioning is often very effective. The principle of reinforcement
has been become one of the most powerful tools in psychology and has
been successfully applied across a range of situations including education,
prisons (token economy) and child raising.
Many self-help books incorporate feature of positive reinforcement, recommended self-reward after small victories e.g weight loss.
However many psychologists disagree that we can learn everything we need to know about psychology from observable behaviour. Behaviourism or learning alone cannot fully explain all aspects of human behaviour and experience. Skinner exaggerated the importance of external or environmental factors as influences on behaviour and underestimated biological factors, and cognitive processes.
However, many studies use animals generalised to humans, this is not valid
as humans are different from animals physically and mentally.
Learning through operant conditioning does not take into account genetic/biological differences.
It also does not explain learning through association as Pavlov's study found (classical conditioning).
It also does not explain learning thorugh imitation as Bandura found in his "Bashing Bobo" study.
Extension:
Want to have some fun?! This site lets you 'try out' Operant Conditioning and modify someone's behaviour:
http://epsych.msstate.edu/adaptive/Fuzz/index.html
Try the tutorial at http://psych.athabascau.ca/html/prtut/reinpair.htm
Print this page out!! This site gives you loads of relevant information about Instrumental Condition and refers to lots of studies. You really do need to print it out and highlight key points if you want to get the most from it.
http://www.viterbo.edu/personalpages/faculty/DWillman/p335_op_cond.htm
click here to go to the application of operant conditioning to humans