Judgment and Reasoning Flashcards
Fallacy
Erroneous reasoning in judgement and decision making.
Reasoning
The process of drawing conclusions and the cognitive process by which people start with information and form conclusions that go beyond that information.
There are two types of reasoning:
- Deductive reasoning: Definitely true
- Inductive reasoning: Probably true
Deductive reasoning
Aristotle is the father of deductive reasoning.
In this case, the conclusion definitely follows from the premises.
Syllogism
A simple form of reasoning which is formed by two premises followed by a conclusion.
There are two types of syllogism:
- Categorical
- Conditional
Categorical Syllogism
Relationship between two categories by using statements that begin with “all”, “some”, “none”.
Validity of a Syllogism
A syllogism is valid when the conclusion follows logically from the two premises.
Truth of the content of the syllogism
Here, we look at the content of the premises and we assert if it is true or not.
Conditional Syllogism
Two premises and a conclusion but the first premise have the form of “if … then …”.
There are four types of conditional syllogism:
- Affirming the antecedent
- Denying the consequent
- Denying the antecedent
- Affirming the consequent
Affirming the antecedent
Premise 1: If I study then I will get a good grade
Premise 2: I studied
Conclusion: I will get a good grade
In this example, premise 2 affirms the first part of premise 1 (in bold).
This is always valid.
Denying the consequent
Premise 1: If I study then I will get a good grade
Premise 2: I didn’t get a good grade
Conclusion: I didn’t study
Here, premise 2 denies the second part of premise 1 (in bold).
This type of conditional syllogism is always valid.
Denying the antecedent
Premise 1: If I study then I will get a good grade
Premise 2: I didn’t study
Conclusion: I will not get a good grade
Invalid conclusion
Affirming Consequent
Premise 1: If I study then I will get a good grade
Premise 2: I got a good grade
Conclusion: I studied
Invalid conclusion
Abstract Syllogisms
In a study, participants were asked to say if a given syllogism was valid or not.
The syllogism was given in abstract form, such as
Premise 1: A -> B
Premise 2: A
Conclusion: B
Participants were better at identifying the validity of the syllogism if it was in a real-life context.
Falsification Principle
This principle states that to test a rule, we have to look for situations that would falsify the rule.
Inductive Reasoning
Conclusions with varying degrees of certainty but definitely do not follow from the premises.
Strength of the argument
Factors influencing the strength of an argument:
- Representativeness
- Number of observations
- Quality of evidence
Availability Heuristic
Events that are more easily remembered are judge as being more probably than the ones that are not as easily remembered.
Availability Heuristic Experiment
In an experiment lead by McKelvie, 26 participants were shown one of the two lists:
- Famous men condition (12 famous men names, 14 women names)
- Famous women condition (12 famous women names, 14 men names)
The participants were then asked if there were more men or women names in the given list. The participants that had the Famous men condition list, said that there were more men in the list and vice versa for the participants that got the second list.
Illusory Correlations
This is the idea that we think some correlation might exists but they don’t.
Illusory Correlations Experiment
Psychologists were given a series of descriptions of a Rorschach test and some personality test (which were paired at random).
Psychologists found patterns where there was none.
Why does Illusory Correlations happen?
- Prior expectations
- Confirmation bias
Representativeness Heuristic
The probability that A is a member of class B can be determined by how well the properties of A match the properties of B.
Base rate:
The relative proportion of different classes in the population.
Category Homogeneity
Category properties are shared by all members.
Confirmation bias
The greater likelihood of responding to a piece of evidence if it confirms our beliefs.
Belief Perseverance
Stick to your beliefs
Expected utility Theory
People are rational, so if they have all the information necessary they will make a choice such that they get the maximum expected utility.
Utility
Outcomes that achieve a person’s goals
Expected Emotions
Emotions that people predict they will have for a given outcome.
Expected emotions provide a lot of information about probably emotional outcomes. It doesn’t involve to really feel the emotion. Moreover, it can be made part of the Expected Utility Theory since a good feeling is a good outcome and a bad feeling a bad outcome.
Immediate Emotions
Emotions that are experienced in the moment of decision making and there are two types:
- Integral immediate decisions: emotions related to the act of making a decision.
- Incidental immediate decisions: unrelated to the actual decision
Risk Aversion
The tendency to avoid risks.
Framing Effect
Decisions are affected by how choices are framed.
If they are stated in terms of gains, people tend to take more risks whereas if the choice is given in terms of loses, people tend to be risk-averse.
Damage to the Prefrontal Cortex
Patients with prefrontal cortex damage have deductive reasoning impairment.
