#22 - Doctors in Britain have long suspected that patients

[cd1010]

Hi, I have a q about the question on p. 5-21: "Doctors in Britain have long suspected..."

The explanation for why D is incorrect is that it discusses the effects of wearing sunglasses. I don't understand this? I had read D to be providing an alternate cause. If, for hypochondriacs, glasses signal to others that their health is delicate, then this might be a reason why they wear tinted glasses, and not because they are depressed.

[Chandler H]

Hi, I have a q about the question on p. 5-21: "Doctors in Britain have long suspected..."

The explanation for why D is incorrect is that it discusses the effects of wearing sunglasses. I don't understand this? I had read D to be providing an alternate cause. If, for hypochondriacs, glasses signal to others that their health is delicate, then this might be a reason why they wear tinted glasses, and not because they are depressed.

Hi CD,

You're correct that (D) is an alternate cause. However, we are looking for a necessary assumption. That means that the correct answer, when negated, will basically destroy the original argument. (E) accomplishes that, because if the tinting does dim light enough to depress the wearer, that means that the author has mixed up cause and effect. If (D) is negated, however, it just means that the glasses do not serve as a visual signal for hypochondriacs.

Does that make sense?

[lemonade42]

Hello,

I originally drew my diagram as:
Cause ----------------------> Effect
tinted glasses ------> because the wearer has the tendency to be depressed or hypochondriacal

because I thought the word "when" in "when such glasses..." was a sufficient condition indicator, so I put it on the left. But then when I put the rest of the conclusion on the right, the "because" made the depression statement sound strange to be on the effect side. So I think I'm getting confused on when to use certain words like "when" as a sufficient condition indicator and when to treat them as causal statements. Can you help me out?

I also have a question about (E)'s "substantially" part. I read through previous responses towards this question, and I just wanted to double check to see if I got the idea correct. (E) is saying the reversed relationship (glasses --> depression) is not happening at a level that is strong enough ("substantially") to weaken the conclusion (depression --> glasses). So, it's okay that (glasses --> depression) happens, it just can't be happening "substantially" enough that it completely disproves the author's conclusion (depression --> glasses). The author alone just has to believe that the reversed relationship is not happening enough to disprove his conclusion, in order for him to make his conclusion. So (E) doesn't have to say (depression -- glasses) happens all the time.

Sorry for such a long question!

[Hanin Abu Amara]

Hi Lemonade42,

I think your issue is that you’re confusing cause and effect work conditionals. There is no sufficient and necessary conditions in cause and effect.

This is a good forum discussion to review viewtopic.php?t=38685

But if you have access to the PowerScore portal, review lessons 2 and 3.

Here our cause and effect indicator is the word because. Because of wearer has tendency to be depressed they were glasses.

Hope that clears that up.

Now as to AC E, we need E to be an accepted assumption because if the glasses were tainted enough to change someone mood then it would switch the cause and effect. It implies the glasses cause the depression which is contrary to the authors argument.

Hope that makes sense.