Revision (content from lecture #7) Flashcards
Causal Relationships
What events cause other events to occur? E.g. X causes Y
Need sufficient evidence to conclude causality
Alternative explanations
Y causes X
Z causes X and Y
Simply correlation – merely a relationship between X and Y
Correlation does not imply causation
Experimental design
Goal Figure out why something happened or how it came about Why Predict what will happen in the future Form the basis of our decisions
Three conditions for causality
To show one event causes another to occur (i.e., X causes Y) 3 conditions must be met
- X and Y must be correlated
- X must precede Y in time
- All other factors (Z) must be ruled out
Questionable cause for relationships
A causal relationship for which no real evidence exists
→ superstition
X must precede Y in time
Assuming that because two things occurred close in time to one another, the first event caused the second
Eg. The rooster crowed and the sun came up. Therefore the rooster made the sun come up.
Directionality problem
Does X cause Y or does Y cause X?
E.g. does self esteem determine academic achievement or vice versa
Third variable problem
Does an outside or third factor (Z) cause both X and Y?
E.g., Intelligence causes self-esteem and academic achievement?
Can you eliminate all “third” variables?
Selection Bias
Participant variables
- Biological, behavioural, psychological characteristics
- -> E.g., personality traits
Environmental variables
–> E.g., place of residence
Selection bias occurs when participant variables leads to selection of a particular environment
- Increases chance of finding a spurious correlation between participant variables and environmental variables
Problem: self-selection in clinical trials
- Need random sampling and random assignment
Causal Chains
- Causes and effects usually appear as parts of more complex patterns, or a causal chain.
- Situation in which one thing leads to another, which then leads to another, and so on.
- Which cause is the real cause?
Contributory Causes
- A number of causes can also act simultaneously to produce an effect
- Each cause contributes to the final effect
Interactive Causes
Causes
- Rarely operate in isolation
- Influence (and are influenced by) other factors
Interactive Causes
- Reciprocal influences
Deductive Reasoning
Reasoning from premises (i.e., reasons) known or assumed to be true to a conclusion that follows necessarily from these premises
Deductive reasoning moves down from known general reasons to specific facts
i.e., “top-down” approach
Inductive Reasoning
Reasoning from premises assumed to be true to a conclusion supported (but not logically) by the premises
- Premises provide evidence that makes it more or less likely (but not certain) that the conclusion is true
Moving from specific observations to broader generalizations and theories
i.e., “bottom up” approach
Empirical Generalisation
Drawing conclusions about a target population based on observing a sample population
When generalising from a sample, need to consider:
- Is the sample known?
- Is the sample sufficient?
- Is the sample representative?
Reasoning in Psychological research
Inductive reasoning
- Draw conclusions about target population from observing sample population
- Construct theories based on observations
== Beware Texas sharpshooter fallacy
Deductive reasoning
- Theories used to make specific predictions (i.e., hypotheses)
Texas Sharpshooter fallacy
- A man in Texas fires random shots at his barn wall, then paints targets around the holes. His neighbours see the barn wall, and are amazed by his accuracy…
→ In Psychology, what could be wrong with doing something like this ?
- Fitting theories to observations (i.e., painting circles around the holes) is not good science
- Good science is conducted by first developing a theory and then gathering observations to test the idea
Fallacious Reasoning
- Unsound arguments that can appear logical
- Often persuasive because they appeal to our emotions
- Often support conclusions we want to believe are accurate
Fallacies of false generalisation
Fallacies of false generalisation:
Hasty generalisation
- Making a general conclusion on the basis of a very small sample
Sweeping generalisation
- Applying a generally accepted conclusion incorrectly in a specific instance
- A glass of wine a night is good for your health
False dilemma
- Forced to choose between two extreme examples without being able to consider additional options
- -> Either/or, black-or-white fallacy
Fallacies of Relevance
Arguments that rely on factors that have little or nothing to do with the argument being made
Appeal to authority
Appeal to tradition:
Ancient wisdom or “mama says…”
Bandwagon:
An uncritical acceptance of others opinions
Appeal to pity:
Conclusion based on feeling sorry
Appeal to fear:
Conclusion based on feeling afraid
Appeal to flattery:
Conclusion based on vanity
Special pleading:
Attempts to make a special exception, without sound justification
We tend to see the world through our own lenses, tilted toward our individual interests
Appeal to ignorance:
Unless something has been proved to be false, it must be true
Often involves shifting the burden of proof
i.e., Claimant asks opponent to disprove conclusion
Begging the question:
The premise of the argument also includes the claim that the conclusion is true
i.e., Circular reasoning
Conclusion: My new diagnostic test for depression is valid and reliable
Premise: Validity and reliability can be established
Straw man:
Exaggerate or distort the opposite opinion, therefore making it easier to attack or discredit
Person A: We should relax the laws on marijuana
Person B: No, any society with unrestricted access to drugs loses its work ethic and goes only for immediate gratification
Red herring:
Introducing an irrelevant topic in order to divert attention away from the original issue
Appeal to personal attack:
Attack the person, not their argument (ad hominem)
Two wrongs make a right:
Attempt to justify a morally questionable action by arguing that it is a response to another wrong action
Actions are independent of each other and each must be evaluated on its own merits
“Capital punishment is fine, since those the government kills don’t have any qualms about killing others”
