Chapter 12: Judgement, Decisions and Reasoning Flashcards
Reasoning
Cognitive processes by which people start with
information and come to conclusions that go beyond that information
Decision
Making a choice between alternatives
Deductive Reasoning
Drawing conclusions about what is true based on a set of premises (purported facts) by applying logic; Draw definite conclusions; All mammals are warm-blooded. A dog is a mammal.
→ Therefore, a dog is warm-blooded.
Inductive Reasoning
Drawing a conclusion about what is probably true based on evidence; Draw probable conclusions; You see many swans and all are white.
→ You conclude all swans are white (even though this may not be true)
Heuristics
Experience based rules that are not guaranteed to provide a correct solution and are mental shortcuts used to make judgments
Availability heuristic
Events more easily remembered are judged as being more probable than those less easily remembered; ow easily examples come to mind when estimating the likelihood of an event; Thinking shark attacks are common after watching the news—even if they’re statistically rare
Illusory correlations heuristic
Correlation thought to exist, but either does not exist or is much weaker than assumed; tendency to perceive a relationship between two variables when none actually exists, or to overestimate the strength of a relationship that does exist
Base Rate
The actual statistical likelihood of something happening, often ignored when people use heuristics.
More truck drivers than literature professors → more likely the poetry-lover is a truck driver
Representativeness heuristic
relies on how well an event seems to represent or match a specific prototype or stereotype; probability that A (person, item, etc.) comes from B (group, category, etc.) can be determined by how well A resembles properties of B; thinking someone who loves poetry is more likely to be a professor than a truck driver, despite base rates
Conjunction rule
probability of two events happening together (A and B) cannot be greater than the probability of either event happening alone (A or B);
p(A and B) must be <= p(A) and <=p(B)
Law of large numbers
emphasizes the human brain’s limited ability to accurately comprehend large numbers, often simplifying them into categories like “many” or “a lot; the larger the number of random samples, the better the estimate provided by the sample
The confirmation bias
Tendency to selectively look for information that conforms to our hypothesis and overlook information that argues against it
My-side bias
tendency to process information in a way that supports one’s own prior beliefs and opinions, while rejecting information that contradicts them
Backfire Effect
People when presented with information that contradicts their beliefs, become more confident in their original beliefs, even if the new information is accurate
Syllogism
a logical argument that uses deductive reasoning to arrive at a conclusion based on two or more premises consisting 3 parts: a major premise (a general statement), a minor premise (a specific statement), and a conclusion
Categorical syllogism
a type of deductive reasoning task where participants evaluate the validity of a conclusion based on two premises that relate to the category memberships of terms; All birds are animals. All parrots are birds. → All parrots are animals
Validity
A syllogism is valid when its conclusion follows logically from its premises and is based only on its form (is it logical); does not depend on truth
Truth
The conclusion of a syllogism is true if it correspond to real world
Belief Bias
A tendency to believe that a syllogism is valid if the conclusion is believable
e.g., it is believable that some students are tired
Mental Model Approach
We visualize situations in our minds to evaluate logical arguments, which are simplified versions of reality used for understanding, reasoning, and decision-making
Conditional syllogisms
Draw a conclusion based on whether or not premise p
is true; “If p, then q”; If it rains, the ground gets wet
Antecedent vs Consequent
- the conditional premise p may/may not be true “if”
- q the consequence of p being true “then”
Modus Tollens
a form of logical inference where, given a conditional statement If P, then Q.
Not Q.
→ Therefore, not P
Affirming the Consequent
a logical fallacy in cognitive psychology where someone incorrectly assumes that if the “then” part of a conditional statement (the consequent) is true, then the “if” part (the antecedent) must also be true; If P, then Q.
Q.
→ Therefore, P