Journalist: Scientists took blood samples from two large, diverse groups of volunteers. All the volunteers in one gro...

Victoria on September 13, 2019

Hi @Minerva,

The journalist argues that "a dislike of vegetables is, at least in some cases, genetically determined."

Why? Because scientists took blood from two groups of volunteers - one group liked vegetables and the other did not - and found that those who liked vegetables all had the gene XRV2G.

What is wrong with this argument? We don't know anything about the genetic makeup of the other group. We know that all those who dislike vegetables have the gene XRV2G, but we don't know if the other group also had this gene.

C is incorrect because it does not address the flaw in the argument. There are two different ways to read this answer choice:

1) When one phenomenon (disliking vegetables) always produces another phenomenon (gene)...

This is impossible. Disliking something cannot change your genetic makeup.

2) When one phenomenon (gene) always produces another phenomenon (disliking vegetables), the latter phenomenon (disliking vegetables) may often be present when the former (gene) is absent.

This is backwards. The flaw in the argument is that the gene may be present in those who like vegetables. We don't have enough information to suggest that many people who dislike vegetables do not have the gene.

Hope this helps! Please let us know if you have any further questions.