Deductive Reasoning
what are the two types of deductive reasoning?
•Conditional (propositional) reasoning
–Relationship between 2 conditions
–If…..then
–Judged as valid or invalid
and
•Syllogism
–2 statements that we must assume to be true, plus a conclusion
–All, none, some
–Judged as valid, invalid, or indeterminate
What is a representative heuristic?
we judge that a sample is likely if it is similar to the population from which it is sampled.
–Random-looking outcomes are judged to be more likely than orderly outcomes
–So persuasive that people often ignore important statistical information that they should consider
what is the framing effect?
•the outcome of your decision can be influenced by 2 factors
–The background context of the choice
–The way in which the question is worded
what is myside bias?
•Overconfidence that one’s own view is correct in a confrontational situation
–often results in conflict
–cannot even consider the possibility that their opponent’s position may be at least partially correct
what is ecological rationality?
–people create a wide variety of heuristics to help them make useful, adaptive decisions in the real world
which ones are valid versus invalid for making decisions?
•Affirming the antecedent
–You say the “if” part is true
–Typically leads to a valid conclusion
•Affirming the consequent
–You say the “then” part is true
–Typically leads to invalid conclusion
•Denying the antecedent
–You say the “if” part is false
–Typically leads to invalid conclusion
•Denying the consequent
–You say the “then” part is false
–Typically leads to valid conclusion
estimate frequency or probability in terms of how easy it is to think of relevant examples
what is the prospect theory?
–tendency to think of gains different than losses
1.When dealing with possible gains (e.g., lives saved), people tend to avoid risks
2.When dealing with possible losses (e.g., lives lost), people tend to seek risks
what is hindsight bias?
•“knew it all along” effect
–After an event happens, we say it was inevitable/obvious from the start
–Overconfidence that we could have predicted it
what is anchoring and adjusting heuristic?
•a first approximation serves as an anchor, and then we adjust
•Generally useful, but typically fail to make large enough adjustments
•Explains our errors when we estimate confidence intervals
–We usually supply ranges that are too narrow, given our uncertainty about the anchor
what impact does negative wording have on our decision making?
People handle positive information better than negative information
–Take longer
–More errors
what are the consequences of the availability heuristic?
It is called the Illusory Correlation.
Occurs when people believe that two variables are statistically related, even though there is no real evidence for this relationship
what is overconfidence?
•confidence judgments are higher than they should be, based on your actual performance on a task
what is a maximizer?
•tend to examine as many options as possible (maximizing decision-making style)
–may lead to “choice overload”
what is a confidence interval?
•range within which we expect a number to fall a certain percentage of the time
What are the four conditional statements for making decisions?
If A (antecedent), then B (consequent)
•Affirming the antecedent: A, therefore B
–You say the “if” part is true
–Typically leads to a valid conclusion
•Affirming the consequent: B, therefore A
–You say the “then” part is true
–Typically leads to invalid conclusion
•Denying the antecedent: Not A, therefore not B
–You say the “if” part is false
–Typically leads to invalid conclusion
•Denying the consequent: Not B, therefore not A
–You say the “then” part is false
–Typically leads to valid conclusion
what factors can affect the representative heuristic?
•Sample size – we ignore sample size when it does matter
•Base rate – we ignore how often something occurs in a population
•Conjunction rule – we often ignore that the probability of a “conjunction” of 2 events cannot be larger than the probability of either of the individual events
How are we able to reduce overconfidence?
its called The crystal-ball technique.
–imagine a completely accurate crystal ball that says that your hypothesis is wrong!
•Forced to alternative explanations for the outcome
what is a sacrificer?
tend to settle for something that is satisfactory (satisficing decision-making style)
What is the base rate fallacy?
•we emphasize the representativeness while underemphasizing the base rate of occurrence
–Ignored the fact that 10/100 were teachers and went based on how representative Mary was of teachers
What are the two types of dual processing of reasoning and decision making?
–Type I Processing = fast and automatic, requiring little conscious attention
•Facial recognition, automatic stereotyping
–Type II Processing = slow and controlled, requiring focused attention
•More accurate: more in depth analysis of Type 1 processing
what factors can impact the availability heuristic
•Recency = the more recent the examples, the more easy they come to mind
–On the news last night vs. 2 months ago
•Familiarity = the more familiar we are with an example, the easier it comes to mind
–On the news every other day vs. never
•Recognition = if you recognize one option but not the other, they conclude it occurs more frequently
–This strategy generally leads to an accurate decision
–Which city has the largest population?
•Milan or Modena?
Planning fallacy = we underestimate the amount of time/money necessary to complete a project
–if there is a default option, then people will choose it
what is deductive reasoning?
•we emphasize the representativeness while underemphasizing the base rate of occurrence
–Ignored the fact that 10/100 were teachers and went based on how representative Mary was of teachers