10.1
How people reason 1: analogies and induction
William James = pointed out the ability to see similarities where others don’t notice
them is what distinguishes excellent reasoners from the rest.
2 kinds of reasoning: analogical and inductive.
Analogies as foundations for reasoning
Analogy = any perceived similarity between otherwise different objects
Analogy = similarity in behaviors between entities that are in other respects quite
different from each other.
Analogies are based on similarity relations.
If someone is not familiar with one set of relations, the similarity with another
relationship will not be used.
Use of analogies in scientific reasoning
Darwin: came up with the concept of natural selection as the mechanism of evolution
partly by seeing the analogy between the selective breeding of plants and animals by
humans and the selective breeding that occurs in nature.
Analytic thinking provides scientists with analogies to assist their understanding of the
natural world and is also associated with a more skeptical view of the world in general.
Use of analogies in judicial and political reasoning and persuasion
Lawyers and politicians frequently use analogies to convict others of some claim.
Analogies are a fundamental component of human thought and persuasion.
Neurological basis of analogical reasoning
The prefrontal cortex is involved in analogical reasoning.
Anterior prefrontal cortex = activated when making semantic decisions.
Multiple areas of the prefrontal cortex = activated when making analogical decisions.
Inductive reasoning and some biases in it
Induction = the attempt to infer some new principle form observations that serve as
clues.
Inductive reasoning = reasoning that is founded on perceived analogies.
Psychologist have focussed more on the mistakes of inductive reasoning than the
successes -> this led to identification of biases in our reasoning, based on the ‘fast’
thinking system.
The availability bias
When we reason, we tend to rely too strongly on information that is readily available
to us and ignore information that is less available.
It can have some serious negative consequences when it occurs in a doctor’s office ->
misdiagnosis.
The confirmation bias
Scientist should design studies aimed at disconfirming their currently held hypotheses.
One can never prove absolutely that a hypothesis is correct, but one can prove
absolutely that is is incorrect.
Confirmation bias = tendency to try to confirm rather dan disconfirm a hypothesis.
, The predictable-world bias
Superstitions often arise because people fail to realize that coincidences are just
coincidences.
Maximizing = choosing the same strategy every trial.
Matching= vary guesses over trial in a way that matches the probability.
Predictable-world bias = a tendency to engage in inductive reasoning even in
situations where such reasoning is pointless because the relationship in question is
completely random.
10.2
How people reason 2: deduction and insight
Deductive reasoning = the attempt to derive logically the consequences that must be
true if certain premises are accepted as true. -> logical proof, assuming that the
premises really are true.
The concrete nature of deductive reasoning
In the past: psychologists believed that deductive reasoning is fundamentally a logical
process best understood in mathematical terms.
Today: relatively few psychologists accept this abstract logic view of deductive
reasoning.
Reason = studies have shown that our natural inclination is to solve deductive
problems by reflecting on our real-world knowledge, not by thinking about law of logic.
Deductive problems: logic or content?
The content of the statements in the problems that need to be solved do matter.
The bias for using knowledge rather than formal logic in answering deductive
reasoning questions can be construed as a bias for thinking inductively rather than
deductively.
Deontic reasoning = reasoning about what one may, should or ought to do, whereas
the abstract problems reflect descriptive or indicative reasoning, which implies only a
description of facts without any violation of social rules.
Elements of insight
Insight problems = problems that are specifically designed to be unsolvable until one
looks at them in a way that is different from the usual way. They entail a mix of
inductive reasoning and deductive reasoning.
An example of an insight problem
Candle problem = subjects are given a candle, matches and a box of tacks and are
asked to attach the candle to a bulletin board in such a way that the candle can be lit
and will burn properly.
Breaking out of a mental set: broadening perception and thought
Mental set = a well-established habit of perception or thought.
Insight problems are difficult, because their solution depends on abandoning a mental
set.
Functional fixedness= the failure to see an object as having a function other than its
usual one.
Discovering a solution
How people reason 1: analogies and induction
William James = pointed out the ability to see similarities where others don’t notice
them is what distinguishes excellent reasoners from the rest.
2 kinds of reasoning: analogical and inductive.
Analogies as foundations for reasoning
Analogy = any perceived similarity between otherwise different objects
Analogy = similarity in behaviors between entities that are in other respects quite
different from each other.
Analogies are based on similarity relations.
If someone is not familiar with one set of relations, the similarity with another
relationship will not be used.
Use of analogies in scientific reasoning
Darwin: came up with the concept of natural selection as the mechanism of evolution
partly by seeing the analogy between the selective breeding of plants and animals by
humans and the selective breeding that occurs in nature.
Analytic thinking provides scientists with analogies to assist their understanding of the
natural world and is also associated with a more skeptical view of the world in general.
Use of analogies in judicial and political reasoning and persuasion
Lawyers and politicians frequently use analogies to convict others of some claim.
Analogies are a fundamental component of human thought and persuasion.
Neurological basis of analogical reasoning
The prefrontal cortex is involved in analogical reasoning.
Anterior prefrontal cortex = activated when making semantic decisions.
Multiple areas of the prefrontal cortex = activated when making analogical decisions.
Inductive reasoning and some biases in it
Induction = the attempt to infer some new principle form observations that serve as
clues.
Inductive reasoning = reasoning that is founded on perceived analogies.
Psychologist have focussed more on the mistakes of inductive reasoning than the
successes -> this led to identification of biases in our reasoning, based on the ‘fast’
thinking system.
The availability bias
When we reason, we tend to rely too strongly on information that is readily available
to us and ignore information that is less available.
It can have some serious negative consequences when it occurs in a doctor’s office ->
misdiagnosis.
The confirmation bias
Scientist should design studies aimed at disconfirming their currently held hypotheses.
One can never prove absolutely that a hypothesis is correct, but one can prove
absolutely that is is incorrect.
Confirmation bias = tendency to try to confirm rather dan disconfirm a hypothesis.
, The predictable-world bias
Superstitions often arise because people fail to realize that coincidences are just
coincidences.
Maximizing = choosing the same strategy every trial.
Matching= vary guesses over trial in a way that matches the probability.
Predictable-world bias = a tendency to engage in inductive reasoning even in
situations where such reasoning is pointless because the relationship in question is
completely random.
10.2
How people reason 2: deduction and insight
Deductive reasoning = the attempt to derive logically the consequences that must be
true if certain premises are accepted as true. -> logical proof, assuming that the
premises really are true.
The concrete nature of deductive reasoning
In the past: psychologists believed that deductive reasoning is fundamentally a logical
process best understood in mathematical terms.
Today: relatively few psychologists accept this abstract logic view of deductive
reasoning.
Reason = studies have shown that our natural inclination is to solve deductive
problems by reflecting on our real-world knowledge, not by thinking about law of logic.
Deductive problems: logic or content?
The content of the statements in the problems that need to be solved do matter.
The bias for using knowledge rather than formal logic in answering deductive
reasoning questions can be construed as a bias for thinking inductively rather than
deductively.
Deontic reasoning = reasoning about what one may, should or ought to do, whereas
the abstract problems reflect descriptive or indicative reasoning, which implies only a
description of facts without any violation of social rules.
Elements of insight
Insight problems = problems that are specifically designed to be unsolvable until one
looks at them in a way that is different from the usual way. They entail a mix of
inductive reasoning and deductive reasoning.
An example of an insight problem
Candle problem = subjects are given a candle, matches and a box of tacks and are
asked to attach the candle to a bulletin board in such a way that the candle can be lit
and will burn properly.
Breaking out of a mental set: broadening perception and thought
Mental set = a well-established habit of perception or thought.
Insight problems are difficult, because their solution depends on abandoning a mental
set.
Functional fixedness= the failure to see an object as having a function other than its
usual one.
Discovering a solution
