Watson-Glaser Critical Thinking Appraisal Evaluating Causal Relationships 1 — Questions and Answers
Question 1: A study finds that cities with more ice cream sales have higher drowning rates. A researcher concludes that ice cream causes drowning. What is the most critical flaw?
- A confounding variable (hot weather) likely explains both trends. (Correct answer)
- The sample size of the study was too small.
- Ice cream sales data is unreliable.
- Drowning rates are always underreported.
Correct answer: A confounding variable (hot weather) likely explains both trends.
Hot weather increases both ice cream consumption and swimming, making weather the common cause rather than a direct causal link.
Question 2: Every time employee morale surveys score high, productivity increases the following quarter. A manager concludes that high morale causes productivity gains. What must be considered?
- Reverse causation is possible — rising productivity may lift morale first. (Correct answer)
- Survey methods are always biased.
- Productivity data lags by more than one quarter.
- Managers influence both morale and productivity equally.
Correct answer: Reverse causation is possible — rising productivity may lift morale first.
Correlation can run in either direction; higher productivity expectations may boost morale, not the other way around.
Question 3: A new training program was introduced in January. Errors dropped by 20% in February. The HR team declares the training caused the drop. Which alternative explanation weakens this claim most?
- A separate process improvement was also implemented in January. (Correct answer)
- The training lasted only two days.
- Some employees did not attend the training.
- February historically has fewer working hours.
Correct answer: A separate process improvement was also implemented in January.
If another intervention occurred simultaneously, it is impossible to isolate the training as the cause.
Question 4: Research shows people who eat breakfast regularly earn higher incomes. A public health report states: 'Eating breakfast boosts earning potential.' What reasoning error is present?
- Confounding variables such as socioeconomic status likely explain both habits. (Correct answer)
- The report uses income data that is outdated.
- Sample selection excluded part-time workers.
- Breakfast nutritional quality was not measured.
Correct answer: Confounding variables such as socioeconomic status likely explain both habits.
Higher socioeconomic status correlates with both stable breakfast habits and higher earnings, making it the likely common cause.
Question 5: A company notices that departments with standing desks report fewer sick days. They plan to give all employees standing desks to cut absenteeism. What critical thinking concern applies?
- Self-selection bias: healthier employees may have chosen standing desks. (Correct answer)
- Standing desks are too expensive to scale company-wide.
- The sick day data may not be accurately recorded.
- Standing desks are only beneficial for certain roles.
Correct answer: Self-selection bias: healthier employees may have chosen standing desks.
If only health-conscious employees opted into standing desks, the correlation reflects their pre-existing habits, not the desks' effect.
Question 6: Post hoc ergo propter hoc is a logical fallacy in which:
- An event following another is assumed to be caused by it. (Correct answer)
- A cause is assumed to always produce the same effect.
- Two simultaneous events are both called causes.
- A general rule is applied incorrectly to a specific case.
Correct answer: An event following another is assumed to be caused by it.
The fallacy 'after this, therefore because of this' confuses temporal sequence with causation.
Watson-Glaser Critical Thinking Appraisal Evaluating Causal Relationships 1
A study finds that cities with more ice cream sales have higher drowning rates.
A researcher concludes that ice cream causes drowning.
What is the most critical flaw?