Q5 - Researchers examined 100 people suffering from

[ohthatpatrick]

Question Type:
Strengthen

Stimulus Breakdown:
Conclusion: The genetic defect increases the risk of herniated disks.
Evidence: 5 out of 100 people with herniated disks have the gene defect. 0 out of 100 people without herniated disks have the gene defect.

Answer Anticipation:
Q4 and Q5 are back to back correlation vs. causality arguments! How fun?

Our most important pushback against causal arguments is, "How ELSE could we interpret the evidence?".

Can we think of a different way to explain why the 5 people with the gene defect were all found in the herniated disk group?
- it's just a coincidence ... 200 ppl isn't a huge sample
- having the herniated disk causes the gene defect
- the gene defect accompanies some OTHER characteristic that leads to a herniated disk, but the gene itself is not causing the herniated disk.

The second pushback against causal arguments is, "How PLAUSIBLE is the author's explanation?" Is there more data beyond this research study that would corroborate these findings?

Correct Answer:
C

Answer Choice Analysis:
(A) 80% of people with the correct gene had herniated backs. That sounds like it would weaken this argument.

(B) 2% of people with the defective gene had herniated backs. It's hard to know whether that strengthens because it seems very low (like it might weaken), but if only 0.4% of people with the correct gene have herniated backs, then 2% is actually a strengthener.

(C) YES! This seems like more evidence to corroborate the theory. This gives us more examples of people with the defective gene who also have herniated disks (of the 30 ppl who have the defective gene, 100% of them have herniated disks)

(D) This sounds like a weakener. The author's team found that 5% of herniated ppl had the bad gene. This other team found that 0% of herniated ppl had the bad gene. So this undermines the author's evidence.

(E) This is another weakening mismatch. Of the 30 ppl with a correct gene, 67% of them had herniated disks.

Takeaway/Pattern: While Flaw, Weaken, Evaluate, and Nec Assumption questions usually deal with Causal Arguments by looking at OTHER WAYS we could explain or interpret the evidence, Strengthen questions more frequently deal with Causal Arguments by giving us Plausibility answers, specifically of the covariation variety.

Covariation is a fancy word for "whether cause and effect seem to appear / disappear together".
We can strengthen causal arguments with examples of "Cause, Effect" or of "No Cause, No Effect". We can weaken causal arguments with examples of "Cause, No Effect" or of "No Cause, Effect".

A, D, and E all gave us Weaken covariation examples of the "No Cause, Effect" variety (people did NOT have the defective gene, but they DID have the herniated disk)

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