#24 - People who have experienced a traumatic event but who

[LSAT2HARD]

I figured it out.

According to the stimulus, there are two groups of people: those who experience traumatic events and those who don't. Among those who experience traumatic events, there are also two groups of people: those who have PTSD and those without. Therefore, we have three groups of people.

Group 1) Traumatic events with PTSD

Group 2) Traumatic events without PTSD

Group 3) No Traumatic events and no PTSD (normal people)

According to the stimulus, group 2 shows a higher HC level than group 3, but information about group 1 is missing.

Group 1) Traumatic events with PTSD: HC level ???

Group 2) Traumatic events without PTSD: HC level high

Group 3) No Traumatic events and no PTSD (normal people): HC level low

Based on this, the author concludes that Traumatic affects the HC level.

Answer B says producing more HC prevents PTSD.
HC level high No PTSD
Counterpositive: PTSD HC level low

Therefore, answer B fills the blank information of group 1.
Group 1) Traumatic events with PTSD: HC level low

However, remember that the author claims it is a traumatic event that affects HC level? So the HC level of group 1 is supposed to be high. Thus, B provides a contradictory situation of the stimulus.

I have to say the reverse causality explanation cannot work for me. Through this viewpoint, I think someone who is as confused as me may get a better understanding of this question.

[Adam Tyson]

Your Covid example is excellent, LSAT2Hard, and absolutely does show reversed cause and effect in much the same way the correct answer does here. In your example, the antibodies aren't high because Covid caused them to be that way. They already WERE high in this population, and that is why Covid didn't kill them!

In the same way, answer B is suggesting that trauma didn't raise the cortisone level. Instead, these people already high levels of cortisone, and that's why they didn't get PTSD. In other words, the high cortisone levels preceded the trauma and that is what caused them to be in this group (having trauma but not having PTSD). This group will have higher cortisone levels on average than the general non-traumatized population because the general population includes people who have high cortisone and people who do not, with the latter group bringing down the average cortisone level for the whole group.

It's not about showing that the group with PTSD got the opposite result, but showing that what put them in that group was that they already had lower cortisone levels.

Think of it chronologically: Answer B is saying the Effect (high cortisone levels) came before the Cause (Trauma with no PTSD). Effect before Cause, aka Effect without Cause, is a classic way to weaken a causal argument!

[merkvslsat]

Is the logic I used to solve this faulty?


Premise: experience trauma -> NOT develop PTSD -> produce higher levels of cortisone
A -> ~B -> C

Conclusion: A --> C

since AC B says that C -> ~B this hurts the argument through reverse causality since its the wrong contrapositive of the relationship b/t B and C the correct one would b ~C-> B
hope I'm not crazy

[merkvslsat]

Is the logic I used to solve this faulty?


Premise: experience trauma -> NOT develop PTSD -> produce higher levels of cortisone
A -> ~B -> C

Conclusion: A --> C

since AC B says that C -> ~B this hurts the argument through reverse causality since its the wrong contrapositive of the relationship b/t B and C the correct one would b ~C-> B
hope I'm not crazy

Indeed I am it’s A + ~B —> C
Conclusion ignores relationship b/t B and C

[Robert Carroll]

Is the logic I used to solve this faulty?


Premise: experience trauma -> NOT develop PTSD -> produce higher levels of cortisone
A -> ~B -> C

Conclusion: A --> C

since AC B says that C -> ~B this hurts the argument through reverse causality since its the wrong contrapositive of the relationship b/t B and C the correct one would b ~C-> B
hope I'm not crazy

Indeed I am it’s A + ~B —> C
Conclusion ignores relationship b/t B and C

merkvs,

I think your latest post (If trauma and NOT PTSD then increased cortisol) is an accurate but incomplete diagram. It's not a conditional relationship we have, but a cause and effect relationship. A causal relationship will generally imply a conditional relationship, so what you said isn't incorrect, but it's incomplete, because the relationship is more than just conditional. There's a lot missing from it. I do think, though, that you understand why this argument is bad and how answer choice (B) weakens it. Take your conditional: (A + B) C. Before anyone concludes A C from that, I'd ask "What about when A and B are both true? Is C true then? We know that A and the absence of B leads us to expect C; what about A and the presence of B?"

As I said, though, thinking of this in conditional terms is missing a lot of what's involved in the relationships. So keep it purely in terms of causation: "When A is present and B is absent, C is also present. So A produces C." That's not necessarily true - maybe A, the negation of B, and the presence of C are all correlated because A and C produce B's absence. That's what answer choice (B) says.

Robert Carroll

[mkloo11]

Hi, thanks to everyone who already hashed out so much of this question. The causation reading makes sense to me now, but only after reading many many many of these posts. So I'm not sure that I could have gotten there myself under test conditions.

I incidentally got this question correct, but not because I understood B. Rather, I ruled out the rest as either strengthening or not impacting the conclusion. Could someone gut-check whether these seem like valid reasons for eliminating the other choices, as alternative approach to this question?

Conclusion: Experiencing a traumatic event can affect how much cortisol one produces in response to stress.

A: Doesn't impact conclusion. We're concerned with the effects of experiencing a traumatic event, and this answer choice deals with people who haven't experienced a traumatic event.
C: In line with the conclusion. Says that people who've experienced traumatic events produce more cortisol in less severely stressful situation than they would had they not experienced a traumatic event. (I.e., traumatic experience has affected cortisol level in stressful situations)
D: Doesn't impact conclusion. Doesn't relate to the affects of experiencing a traumatic event on cortisol/stress; discusses effects of PTSD treatments.
E: Directly supports conclusion. Explains how experiencing of a traumatic event affects cortisol production.

Then with only B left, I could sort of squint to see that it might attack the premise. It vaguely seemed to suggest that cortisol levels affect traumatic experience, which is the reverse of the conclusion. But I only recognized this enough to not second-guess my other eliminations. And fortunately the only one I had as a remaining contender.

Obviously, it would be ideal to see the causation link clearly as others have kindly laid out here. But if I were to rely on plan B (as I did), does this reasoning seem okay? Thanks very much!

[Rachael Wilkenfeld]

Hi mkloo,

Great work in getting this right! It's great that you are taking the time in review to really dig into the answer choices. Remember though, on test day, any way you get to that right answer choice is worth the same exact point. Hopefully, you'll get to the point where you can see why the answer choices are wrong, and understand why the right answer is correct.

I'd be a bit more descriptive in your conclusion. You did a good job of pulling it out of the stimulus, but we want to give more information/context where we can. It's not just that traumatic events can affect cortisol production. It's specifically that experiencing a traumatic event WITHOUT getting PTSD causes higher levels of the hormone cortisol. We have a direction given in the stimulus, so we want to include it in our idea of the conclusion.

Answer choice (A): This would not have an effect. It's a description of the absence of the cause (traumatic event) with an undetermined effect. We don't know if it's saying the cortisol level goes up or down. We can't tie it to the causal relationship in the stimulus.

Answer choice (B): This is our correct answer. It states that the higher cortisol levels actually cause people who experience traumatic events to avoid PTSD. It's a reversed cause/effect answer choice. That will weaken the causal argument in the stimulus

Answer choice (C): This is wrong for the exact reason you said! It shows where the cause occurs the effect occurs, which would strengthen the stimulus. Good work!

Answer choice (D): Right on again! Our causal relationship is about those who did not experience PTSD. We don't know anything about those who do. It was a causal relationship not described in the stimulus.

Answer choice (E): Exactly right! It strengthens by showing how the cause and the effect are connected.

Really good work here!