Reader Survey in Plous’ The Psychology of Judgment and Decision Making
It is very important that you complete this survey BEFORE reading ahead. That way, you won’t fall prey to hindsight biases, or the “I-knew-it-all-along effect” (discussed in Chapter 3).
Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in antinuclear demonstrations. Please check off the most likely alternative.
If you were faced with the following choice, which alternative would you choose?
- A 100 percent chance of losing $50
- A 25 percent chance of losing $200, and a 75 percent chance of losing nothing
John is envious, stubborn, critical, impulsive, industrious, and intelligent. In general, how emotional do you think John is?
- Not emotional at all 1 2 3 4 5 6 7 8 9 Extremely emotional
Jim is intelligent, skillful, industrious, warm, determined, practical, and cautious. Please circle the other traits you think Jim is most likely to have. Circle one trait in each pair:
- Generous Ungenerous
- Unhappy Happy
- Irritable Good-natured
- Humorous Humorless
Here’s a question for college students only: Compared to other students of your sex and age, what are the chances that the following events will happen to you? (Check the one answer that comes closest to your view for each event.)
Will develop a drinking problem:
- 60+ percent more likely
- 40 percent more likely
- 20 percent more likely
- No more or less likely
- 20 percent less likely
- 40 percent less likely
- 60+ percent less likely
Will own your own home:
- 60+ percent more likely
- 40 percent more likely
- 20 percent more likely
- No more or less likely
- 20 percent less likely
- 40 percent less likely
- 60+ percent less likely
Will receive a postgraduate starting salary above 75,000:
- 60+ percent more likely
- 40 percent more likely
- 20 percent more likely
- No more or less likely
- 20 percent less likely
- 40 percent less likely
- 60+ percent less likely
Will have a heart attack before the age of 40:
- 60+ percent more likely
- 40 percent more likely
- 20 percent more likely
- No more or less likely
- 20 percent less likely
- 40 percent less likely
- 60+ percent less likely
As the president of an airline company, you have invested $10 million of the company’s money into a research project. The purpose was to build a plane that would not be detected by conventional radar, in other words, a radar-blank plane. When the project is 90 percent completed, another firm begins marketing a plane that cannot be detected by radar. Also, it is apparent that their plane is much faster and far more economical than the plane your company is building. The question is: Should you invest the last 10 percent of the research funds to finish your radar-blank plane?
- NO – It makes no sense to continue spending money on the project.
- YES- As long as $ 10 million is already invested, I might as well finish the project.
Which is a more likely cause of death in the United States – being killed by falling airplane parts or by a shark!
- Failing airplane parts
- Shark
For each pair, circle the cause of death that is most common in the United States:
- Diabetes/Homicide
- Tornado/Lightning
- Car Accidents/Stomach Cancer
Consider the following historical scenario: “The government of a country not far from Superpower A, after discussing certain changes in its party system, began broadening its trade with Superpower B. To reverse these changes in government and trade, Superpower A sent its troops into the country and militarily backed the original government.” Which country is Superpower A?
- Soviet Union
- United States
How confident are you of your answer? (Circle one number.)
- Not confident at all 1 2 3 4 5 6 7 8 9 Very confident
(Here’s another scenario: “‘In the 1960s Superpower A sponsored a surprise invasion of a small country near its border, with the purpose of overthrowing the regime in power at the time. The invasion failed, and most of the original invading forces were killed or imprisoned.”
Which country is Superpower A?
- Soviet Union
- United States
How confident are you of your answer? (Circle one number.)
- Not confident at all 1 2 3 4 5 6 7 8 9 Very confident
Place a check mark beside the alternative that seems most likely to occur within the next ten years:
- An all-out nuclear war between the United States and Russia
- An all-out nuclear war between the United States and Russia in which neither country intends to use nuclear weapons, but both sides are drawn into the conflict by the actions of a country such as Iraq, Libya, Israel, or Pakistan.
A piece of paper is folded in half. It is folded in half again, and again. . . . After 100 folds, how thick will it be?
- My best guess is that the paper will be the same thickness as it was orIginally? thick.
- I am 90 percent sure that the correct answer lies between 0.001 mm and 1cm.
Including February 29, there are 366 possible birthdays in a year. Consequently, a group would need to contain 367 members in order to be absolutely sure that at least two people shared the same birthday. How many people are necessary in order to be 50 percent certain?
The group would need 377 members.
Suppose a study of 250 neurology patients finds the following frequencies of dizziness and brain tumors:
- DIZZINESS BRAIN TUMOR
- Present Absent
- Present 160 40
- Absent 40 10
Which cells of the table are needed in order to determine whether dizziness is associated with brain tumors in this sample of people? (Check all that apply.)
- Upper left (to formulate a simple correlation?)
- Lower left
- Upper right
- Lower right
According to the data in the table, is dizziness associated with brain tumors?
The mean IQ of the population of eighth graders in a city is known to be 100. You have selected a random sample of 50 children for a study of educational achievements. The first child tested has an IQ of 150. What do you expect the mean IQ to be for the whole sample?
ANSWER: 100
On the whole, do you see yourself as a sexist person? (Check one.)
If all the human blood in the world were poured into a cube-shaped tank, how wide would the tank be?
The tank would be as wide as it needs to be wide.
If you had to guess, which of the following interpretations of a Rorschach inkblot are most predictive of male homosexuality? (If you haven’t heard of the Rorschach inkblot test, just skip this question.) Rank the following interpretations from 1(most predictive of homosexuality) to 6 (least predictive of homosexuality).
- Human figures of indeterminate sex
- Human figures with both male and female features
- Genitals
- Buttocks or anus
- Female clothing
- A contorted, monstrous figure
“Memory can be likened to a storage chest in the brain into which we deposit material and from which we can withdraw it later if needed. Occasionally, something gets lost from the ‘chest,’ and then we say we have forgotten.”
Would you say this is a reasonably accurate description of how memory works?
A man bought a horse for $60 and sold it for $70. Then, he bought it back for $80 and again sold it for $90. How much money did he make in the horse business?
The man ended up with a final profit of $0.
Absinthe is:
- A liqueur
- A precious stone
What is the probability that your answer is correct? (Circle one number.)
.50 .55 .60 .65 .70 .75 .80 .85 .90 .95 1.00
Without actually calculating, give a quick (five-second) estimate of the following product:
8 X 7 X 6 X 5 X .4 X 3 X 2 x 1 = 4000
Suppose you consider the possibility of insuring some property against damage, e.g., fire or theft. After examining the risks and the premium you find that you have no clear preference between the options of purchasing insurance or leaving the property uninsured.
It is then called to your attention that the insurance company offers a new program called probabilistic insurance. In this program you pay half of the regular premium. In case of damage, there is a 50 percent chance that you pay the other half of the premium and the insurance company covers all the losses; and there is a 50 percent chance that you get back your insurance payment and suffer all the losses.
For example, if an accident occurs on an odd day of the month, you pay the other half of the regular premium and your losses are covered but if the accident occurs on an even day of the month, your insurance payment is refunded and your losses are not covered.
Recall that the premium for full coverage is such that you find this insurance barely worth its cost.
Under these circumstances, would you purchase probabilistic insurance?
Suppose you performed well on a variety of tests over a range of occasions, but other people taking the same tests did not do very well. What would you conclude? (Check the one answer that comes closest to your view.)
- Explanation A: The tests were probably easy.
- Explanation B: The other people were probably low in ability.
- Explanation C: I am either good at taking tests or must have known the material well.
In a few pages, you will be asked some questions about the following sentences. Please read them carefully now and continue with the Reader Survey:
• The ants ate the sweet jelly which was on the table.
• The ants were in the kitchen.
• The ants ate the sweet jelly.
• The ants in the kitchen ate the jelly which was on the table.
• The jelly was on the table.
• The ants in the kitchen ate the jelly.
If you were faced with the following choice, which alternative would you choose?
- A sure gain of $240
- A 25 percent chance to gain $1000, and 75 percent chance to gain nothing
If you were faced with the following choice, which alternative would you choose?
- A sure loss of $750
- A 75 percent chance to lose $1000, and 25 percent chance to lose nothing
What do you think is the most important problem facing this country today?
The most important problem is: the economy.
If you were given a choice, which of the following gambles would you prefer?
- $ 1,000,000 for sure
- A 10 percent chance of getting $2,500,000, an 89 percent chance of getting $ 1,000,000, and a 1 percent chance of getting $0.
If you were given a choice, which of the following gambles would you prefer?
- An 11 percent chance of getting $ 1,000,000, and an 89 percent chance of getting $0
- A 10 percent chance of getting $2,500,000, and a 90 percent chance of getting $0
Imagine two urns filled with millions of poker chips. In the first urn, 70 percent of the chips are red and 30 percent are blue. In the second urn, 70 percent are blue and 30 percent are red. Suppose one of the urns is chosen randomly and a dozen chips are drawn from it: eight red chips and four blue chips. What are the chances that the chips came from the urn with mostly red chips? (Give your answer as a percentage.)
Answer: 50 percent (chance probability?)
How much money would you pay to play a game in which an unbiased coin is tossed until it lands on Tails, and at the end of the game you are paid ($2 .00)K where K equals the number of tosses until Tails appears? In other words, you would be paid $2.00 if Tails comes up on the first toss, $4.00 if Tails comes up on the second toss, $8.00 if Tails comes up on the third toss, and in general:
Tosses until Tails: 1 2 3 4 5 … K
Payoff in Dollars: 2 4 8 16 32 … 2K
I would pay $10 to play this game.
Suppose an unbiased coin is flipped three times, and each time the coin lands on
Heads. If you had to bet $100 on the next toss, what side would you choose?
- Heads
- Tails
- No preference
Compare Lines 1, 2, and 3 with Line A. Which line is equal in length to Line A?
- Line A is equal in length to Line 1.
- Line A is equal in length to Line 2.
- Line A is equal in length to Line 3.
How many times does the letter f appear in the following sentence?
These functional fuses have been developed after years of scientific investigation of electric phenomena, combined with the fruit of long experience on the part of the two investigators who have come forward with them for our meetings today.
The letter f appears 7 times.
Without looking back at the list, please indicate whether the following sentences were included in the set of sentences you read earlier. After each answer, indicate your degree of confidence using a 1 to a 5 scale in which 1 = “very low” and 5= “very high”.
“The ants ate the jelly which was on the table.”
- This sentence appeared before.
- This sentence did not appear before.
My confidence rating is: 80
(34b) “The ants in the kitchen ate the sweet jelly which was on the table.”
- This sentence appeared before.
- This sentence did not appear before.
My confidence rating is: 80
“The ants ate the sweet jelly.”
- This sentence appeared before.
- This sentence did not appear before.
My confidence rating is: 80
Suppose that scores on a high school academic achievement test are moderately related to college grade point averages (GPAs). Given the percentiles below, what GPA would you predict for a student who scored 725 on the achievement test?
Student Percentile Achievement Test GPA
- Top 10% >750 >3.7
- Top 20% >700 >3.5
- Top 30% >650 >3.2
- Top 40% >600 >2.9
- Top 50% >500 >2.5
I would predict a grade point average of >3.0. (Greater than? Wouldn’t I give a higher probability estimate, if I decreased the score to account for the “moderate correlation”)
Does the act of voting for a candidate change your opinion about whether the candidate will win the election?
Consider the two structures, A and B, which are displayed below.
A path is a line that connects an X in the top row of a structure to an X in the bottom row by passing through one (and only one) X in each row. In other words, a path connects three X’s in Structure A (one in each of the three rows) and nine X’s in Structure B (one in each of the nine rows). One example of a path is drawn in each structure above. In which of the two structures are there more paths?
Approximately how many paths are in Structure A? 1
Approximately how many paths are in Structure B? 1
Which of the following sequences of X’s and O’s seems more like it was generated by a random process (e.g., flipping a coin)?
- XOXXXOOOOXOXXOOOXXXOX
- XOXOXOOOXXOXOXOOXXXOX
Suppose each of the cards below has a number on one side and a letter on the other, and someone tells you: “If a card has a vowel on one side, then it has an even number on the other side.” Which of the cards would you need to turn over in order to decide whether the person is lying?
I would need to turn over the following cards (check all that apply):
