5.2 Delay and Impulsiveness Flashcards
Appliances studies
Concerns Costs
Question: How do people make a choice between immediate and delayed cost
Protocol: Choice between various appliance models. Cheaper is less efficient. Expensive is more efficient.
2 costs: immediate cost (purchase price) and delayed cost (operating cost: power, maintenance, repairs)
Conditions:
Measuring:
Conclusion: Operating expenses (negative rewards) are discounted. Anywhere from 25% to 300% per year
Can you think of other situations that take advantage of our tendency to discount future costs? Payday loans, businesses selling things
Pigeon discounting 1 - Postponing work
Concerning negative rewards (similar to appliances study)
Question:
Protocol: Pigeons trained using operant conditioning. Random feeding cycles of 20s. Interrupted by choice and later task (-ve work). Two buttons: Green or Red.
Green: Do a bit more work (5 pecks) after 6s
Red: Do more work after 20s
If the amount of work is the same for both choices, which button will the pigeons prefer to choose? They would choose RED.
How many pecks does it take to break even (50/50 between red and green) in the RED button case (more work later)? More than 5 pecks. They are willing to do more in order to wait longer
Conditions:
Measuring:
Conclusion: Break even point: 30 pecks after 20s = 5 pecks after 6s. The pigeons are willing to do 6 times the work, if they can delay that work by 14s. They do a lot more work just because it’s in the future -> temporal discounting.
Mostly because pigeon environment is very unstable. Who knows what might happen in 14 seconds (dog, car, human)
Pigeon discounting 2 - Preference reversal
Focus on delay and positive rewards. Preference reversal add complexity (different choice made in different points of time)
Question:
Protocol: 2 buttons, Green or Red. Lead to different feeding cycles.
Green: Wait 2s | Eat 2s | Wait 6s -> 10s
Red: Wait 4s | Eat 4s | Wait 2s -> 10s
Weighing more or less eating with more or less waiting.
Conditions: 2
A: Wait 28s | Choose 2s | Feeding cycle 10s
B: Choose 2s | Wait 28s | Feeding cycle 10s
Conditions x Choices: A Green: Choose | Wait 2s | Eat 2s A Red: Choose | Wait 4s | Eat 4s B Green: Choose | Wait 30s | Eat 2s B Red: Choose | Wait 32s | Eat 4s Review graph
Which button do we expect in condition A? Green
Which button do we expect in condition B? Red
Measuring:
Conclusion:
A: Vast preference for Green
B: Vast preference for Red
Temporal discounting in short time scale is stronger than long time scale
The amount of temporal discounting for a 2s difference is larger for short delays, and smaller for long delays
Confirms general shape of temporal discounting curve
At some point, the pigeons change their mind. This is the preference reversal
Preference reversal
Review graph
In the value graph for saving and spending, their curves intersect at one point. That is the preference reversal.
Before the reversal, the value for saving is bigger than the value for spending, so we choose to save
As time passes, the spending curve increases more sharply than saving and intersects. Our preference now reverses and we choose spending over saving.
Can we think of a real world example of preference reversal? When we plan to work, the time comes, and we do something else. Ahead of time, it’s easy to say we will work on the assignment. As time advances, it’s easier to do other things.
What can we do if we want to make a wise decision? We make good decisions early on, and worse decision later on. If we have a way to lock in our early decisions, that can be good. This is called pre-commitment.
Impulsiveness in other species
Non-human animals exhibit greater impulsiveness, like pigeons.
Monkeys will choose immediate rewards over significantly larger delayed rewards, even when the delay is only several seconds
Pigeon rewards lose 50% of their value when delayed by a single second
Temporal discounting makes sense if the environment is very unstable.
Old brain vs new brain
Ability for long term planning has much to do with the development of the frontal cortex. The greedy drive is contained in the evolutionary older limbic system
Differences between humans
Categories of people with high impulsiveness: Children Alcoholics Smokers Cocaine and heroin addicts Compulsive gamblers
Low impulsiveness:
Older adults
Ulysses’ dilemma
Talk more about temporal discounting and preference reversal. Ulysses deals with this with a creative suggestion. Example of pre-committing
