Scientists took blood samples from two large, diverse groups of volunt

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Genetics can make you dislike vegetables.

REASONING: Volunteers who don’t like vegetables have the XRV2G gene.

ANALYSIS: the false comparison.

We’re told that the vegetable hating group has XRV2G. But we’re not told about the group that likes vegetables. Maybe all of them also have XRV2G! A proper comparison must tell you about both groups, not just one.

___________

A. The argument didn’t say this. Something can’t be a flaw unless it happens. The argument just said one trait might be genetically determined. It didn’t say all traits are.

B. This answer plays on a misunderstanding of bias and representativeness in studies.

Let’s say you do a study designed to test whether a certain drug cures cancer. And all the subjects are American. Americans are unrepresentative of humans in many ways:

* They’re richer than average
* They live in a country that starts with ‘A’
* They watch more TV
* They have more internet access

C. All of those are unrepresentative, and none of them are relevant to the question of whether a drug cures cancer. So unrepresentativeness in one or more areas does not necessarily mean a study if flawed!
This means: mistaking a sufficient condition for a necessary condition. That’s not what happened in this argument.

D. This possibility would strengthen the argument! It’s not a flaw to overlook it. the conclusion was that genes may affect whether we like vegetables. So the more that genes affect our taste for vegetables, the better.

E. CORRECT. If everyone has the XRV2G gene, then it can’t affect vegetable tastes.