MCAT® ExamPsychological, Social, and Biological Foundations of BehaviorHard
A research team is investigating the genetic basis of a rare neurological disorder. They identify a specific gene mutation consistently present in all affected individuals within several families, but absent in unaffected family members and the general population. The researchers hypothesize that this mutation is directly responsible for the disorder. Which of the following terms best describes the relationship between the identified gene mutation and the neurological disorder?
- AModeration
- BCorrelation
- CCausation
- DConfounding
Show answer & explanationAnswer & explanation
Correct answer: C. Causation
The scenario describes a direct causal link: the gene mutation is consistently present in all affected individuals and absent in unaffected ones, strongly suggesting it is the cause of the disorder, not merely correlated with it. This meets the criteria for causation (temporal precedence, consistent association, and a plausible mechanism).
Why the other options are wrong
- A. Moderation refers to a variable that changes the strength or direction of the relationship between two other variables.
- B. Correlation indicates a relationship between two variables, but not necessarily that one causes the other.
- D. Confounding occurs when an extraneous variable influences both the independent and dependent variables, creating a spurious association.
Causation
A relationship between two events or states where one event (the cause) brings about the other event (the effect). Establishing causation requires more than just correlation.
- Temporal precedence: Cause must precede effect
- Consistent association: Cause and effect must occur together
- Lack of spuriousness: No other variable explains the relationship
- Plausible mechanism: A logical explanation for the link
Memory trick: Causation: 'Cause' and 'Effect' are linked.