POLSCI 240 / PSY 225: Political Psychology
April 14, 2025
If people can’t (or won’t) optimize (maximize expected utility), what alternative decision rules might they use? And how successful are they? What biases might they introduce?
A heuristic is a decision strategy that ignores part of the information - two broad traditions of research:
Heuristics and biases (Kahneman & Tversky)
Bounded rationality / “fast and frugal” decision making (Simon, Gigerenzer)
The availability heuristic uses the ease with which something comes to mind as a substitute for information about prevalence, importance, probability, goodness, etc.
Frequency of repetition and desirability
Importance or weight of different considerations
Taking risks:
The representativeness heuristic assesses the probability that an instance \(A\) belongs to a class \(X\) by the degree to which \(A\) is “representative” of \(X\)
What does it mean for something to be “representative”?
resemblance to prototype or stored representation of \(X\) in memory (e.g., a stereotype of a group)
degree to which \(A\) possesses features diagnostic of \(X\)
Which of the following sequences of tosses of a fair coin is most likely?
This is called the conjunction fallacy
https://thedecisionlab.com/biases/base-rate-fallacy
Stereotypes often focus on large relative differences between groups - traits that are diagnostic rather than common for a group
Only about 10% of Irish people have red hair, but having red hair is much more likely among Irish relative to most other ethnic groups
Many negative stereotypes may be fostered by this kind of cognitive process
# Group A has 1% crime rate, Group B has 2% crime rate
A <- c(0.01, 0.99)
B <- c(0.02, 0.98)
# representativeness of criminality for each group
R_A <- A / B
R_B <- B / A
# stereotype: what is probability that randomly drawn member of group is criminal?
S_A <- A * R_A / sum(A*R_A)
S_B <- B * R_B / sum(B*R_B)
# true difference in probability between groups
true_diff <- B[1] - A[1]
# distorted (stereotyped) diff in probability between groups
stereo_diff <- S_B[1] - S_A[1]
# compare
comp <- round(cbind(true = c(A[1],B[1],true_diff),
stereotype = c(S_A[1],S_B[1],
stereo_diff)), 3)
row.names(comp) <- c("A","B","B-A")
comp
true stereotype
A 0.01 0.005
B 0.02 0.040
B-A 0.01 0.035
“How do human beings reason when the conditions for rationality postulated by the model of neoclassical economics are not met?”
Limitations: human (e.g., cognitive) and contextual (e.g., time, resources, information)
Bounded rationality: reasonable decision making under constraints
https://www.wired.com/story/how-do-people-actually-catch-baseballs/
https://www.wired.com/story/how-do-people-actually-catch-baseballs/
Decision theorists have studied a number of general heuristic decision rules: strategies that can be applied across many decision contexts
Ignore some alternatives
Ignore some attributes
Ignore decision weights
Issue | Abortion | Taxes | Immigration |
---|---|---|---|
Voter’s Position | Pro | Con | Pro |
Importance Weights | 1.0 | 0.5 | 2.0 |
Issue | Candidate 1 | Candidate 2 | Candidate 3 | Candidate 4 |
---|---|---|---|---|
Abortion | Pro | Con | Con | Pro |
Taxes | Con | Con | Con | Pro |
Immigration | Con | Pro | Con | Pro |
Who would the voter choose if they use all information (give +1 times weight for matches and -1 times weight for mismatches)?
Issue | Abortion | Taxes | Immigration |
---|---|---|---|
Voter’s Position | Pro | Con | Pro |
Importance Weights | 1.0 | 0.5 | 2.0 |
Issue | Candidate 1 | Candidate 2 | Candidate 3 | Candidate 4 |
---|---|---|---|---|
Abortion | Pro | Con | Con | Pro |
Taxes | Con | Con | Con | Pro |
Immigration | Con | Pro | Con | Pro |
TOTAL | -0.5 | 1.5 | -2.5 | 2.5 |
Who would voter choose with equal weights?
Issue | Abortion | Taxes | Immigration |
---|---|---|---|
Voter’s Position | Pro | Con | Pro |
Importance Weights | 1.0 | 0.5 | 2.0 |
Issue | Candidate 1 | Candidate 2 | Candidate 3 | Candidate 4 |
---|---|---|---|---|
Abortion | Pro | Con | Con | Pro |
Taxes | Con | Con | Con | Pro |
Immigration | Con | Pro | Con | Pro |
TOTAL | 1 | 1 | -1 | 1 |
Herbert Simon proposed a decision strategy called satisficing
Let’s say the voter’s aspiration level is utility greater than 0
Issue | Abortion | Taxes | Immigration |
---|---|---|---|
Voter’s Position | Pro | Con | Pro |
Importance Weights | 1.0 | 0.5 | 2.0 |
Issue | Candidate 1 | Candidate 2 | Candidate 3 | Candidate 4 |
---|---|---|---|---|
Abortion | Pro | Con | Con | Pro |
Taxes | Con | Con | Con | Pro |
Immigration | Con | Pro | Con | Pro |
DECISION | X | CHOOSE | NOT SEEN | NOT SEEN |
Lexicographic rules consider alternatives on one attribute at a time, in order of importance,
Who will the voter choose using lexicographic?
Issue | Abortion | Taxes | Immigration |
---|---|---|---|
Voter’s Position | Pro | Con | Pro |
Importance Weights | 1.0 | 0.5 | 2.0 |
Issue | Candidate 1 | Candidate 2 | Candidate 3 | Candidate 4 |
---|---|---|---|---|
Abortion | Pro | Con | Con | Pro |
Taxes | Con | Con | Con | Pro |
Immigration | Con | Pro | Con | Pro |
DECISION | X | X | X | CHOOSE |
Elimination by aspects is a rule created by Amos Tversky
Who will the voter choose using EBA (aspiration level is agreement)?
Issue | Abortion | Taxes | Immigration |
---|---|---|---|
Voter’s Position | Pro | Con | Pro |
Importance Weights | 1.0 | 0.5 | 2.0 |
Issue | Candidate 1 | Candidate 2 | Candidate 3 | Candidate 4 |
---|---|---|---|---|
Abortion | Pro | Con | Con | Pro |
Taxes | Con | Con | Con | Pro |
Immigration | Con | Pro | Con | Pro |
DECISION | X | X | X | CHOOSE |
Which of these two cities in Wales has a larger population?
While Kahneman and Tversky studies “availability” as a bias, it will often be a successful strategy!
How can we evaluate how successful these heuristic strategies are?
Define “accuracy” as how well the heuristic rule does compared to the full-information, expected value rule (i.e., the optimizing rule)
Define “efficiency” as the number of “cognitive operations” required to implement the rule, e.g.,
A few categories related to the strategies we have discussed:
“Simple act of voting” (Kelley and Mirer 1974)
“One good cue” methods: leverage information about overlap between your interests and those of prominent political groups
“Issue publics” and lexicographic rules
Converse (1964)
…large portions of an electorate do not have meaningful beliefs, even on issues that have formed the basis for intense political controversy among elites for substantial periods of time…where any single dimension is concerned, very substantial portions of the public simply do not belong on the dimension at all. They should be set aside as not forming any part of that particular issue public…One man takes an interest in [racial issues] and is relatively indifferent to or ignorant about controversies in other areas. His neighbor may have few crystallized opinions on the race issue, but he may find the subject of foreign aid very important. Such sharp divisions of interest are part of what the term “issue public” is intended to convey.
Much work suggests partisanship may be a “standing decision” - but when do people “defect”?
If people care mostly about a small number of issues important to them, they will defect when:
People may not be issue voters in the standard spatial sense, but they may nonetheless be responsive to some issues in campaigns
Process-tracing is the study of decision making by observing the intermediate steps decision makers take to reach a decision