Q21 - Psychologists: Some astrologers claim

[coup999]

21: Psychologists: Some astrologers claim that our horoscopes completely determine our personalities, but this claim is false.....

I don't get why the answer is C. Our geographical differences don't determine horoscopes. Horoscopes are the same for each day no matter where you are located.

[giladedelman]

Ah! Ah! LSAT moment!

You've been done in by your own outside knowledge! Remember, this is the LSAT. What we care about is the logic of an argument, not real-world facts. This argument says:

people born at the same time in Toronto and New York had different personalities ---> horoscope doesn't completely determine your personality.

Notice that the argument doesn't explicitly say that the two people had different horoscopes; it has to assume this is the case.

So (C) is correct because the argument does depend on the assumption that the geographical difference didn't lead to a horoscope difference. It doesn't matter whether this is the case in the real world. We don't care whether the assumption is "true" or not, we care about whether it's necessary for this argument.

Does that make sense? Let me know if you're still not sure about this -- your question is an important one.

[coup999]

Got it. I figured that's what it was but was still held up by the "common sense" notion that different geographies don't mean different horoscopes. Bad brain, bad brain!

[danielleangelareyes]

Is it fair to say that answer choice B actually strengthens the argument and that is why it is incorrect?

[daniel]

Is it fair to say that answer choice B actually strengthens the argument and that is why it is incorrect?

This question is a few months old, but I'll tackle it for practice....

I'd argue that (B) doesn't strengthen the argument: It's just plain out of scope.

The psychologist concludes that the claim that horoscopes completely determine our personalities is false. In other words, horoscopes DO NOT completely determine personalities.

Why?

People born at the same time in two different cities grew up having different personalities.

(B) says that the personality differences CANNOT be explained by the cultural differences that exist between the two cities.

Even if the cultural differences do not / cannot explain the personality differences, that does not impact the conclusion that horoscopes do not completely determine them either. That's why I think this is out of scope.

Now, if (B) said that the personality differences CAN be explained by the cultural differences, then that would strengthen the argument (while still not being a necessary assumption) by suggesting that some other factor aside from the horoscope contributed to each individual's personality (i.e., not completely determined by the horoscope).

[christine.defenbaugh]

Bravo daniel, excellent work!

I completely agree with you that (B) neither strengthens nor weakens, and I further agree with your hypothetical rewrite of (B) to turn it into a strengthener.

For the sake of future students, I'm going to break this question down from the beginning.

For this necessary assumption question, we know that we need to find the core first:

Premise: birth records show two people born @ same time in Toronto and New York that ended up with different personalities.
Conclusion: Horoscopes don't completely determine personality.

When laid out in shortened form this way, it's a bit easier to see the disconnect between "horoscope" in the conclusion and the longer description of "born at same time in different places". "Horoscope" is actually a new term in the conclusion! We have to assume that they are the same thing! (C) zeros right in on that. Negating (C) would produce different horoscopes for these two people, which means they are terrible evidence for this conclusion.

[Side note about outside knowledge: Outside knowledge is dangerous for a number of reasons, but in no small part because it's often wrong. For many versions of horoscope, location does actually matter. You don't need to know that to answer the question though, because you should be suspect of the gap above regardless.]

Bonus Points: There's actually another assumption here that the LSAT chose not to test regarding birth records. Did you see it?


Not Necessarily Assumed
(A) What if they had? Couldn't the astrologers have rigorously experimented on horoscopes and yet their claims are still wrong? Maybe they misinterpreted the results of the experiements. Or maybe they are willfully misrepresenting them? Or maybe their rigorous experiments just happened to be the cases that matched their claims.
(B) This seems to strengthen the astrologers' claim, not the psychologist's. Crossing off 'culture' as an explanation for personality differences doesn't affect the psychologist's claim that horoscope isn't 100% responsible for personality.
(D) What if they weren't complete? As long as these two people's birth records are accurate, this argument still stands. Everyone else's birth records could have been wildly inaccurate, and it wouldn't matter.
(E) This might be tempting if you thought this offered a reasonable explanation for personality similarities of identical twins other than horoscope. But the argument doesn't need it to be true. What if it wasn't? There could still be other causes for personality similarity.


For Necessary Assumption questions, we want to first zero in on our core. The correct answer should be absolutely required for the conclusion to be able to follow - thus, taking it away and negating it should kill the argument dead!

I hope this helps make this question a bit clearer!

[zjce]

thank you all for clarification, but i am still confused about choice b)

"(B) This seems to strengthen the astrologers' claim, not the psychologist's. Crossing off 'culture' as an explanation for personality differences doesn't affect the psychologist's claim that horoscope isn't 100% responsible for personality."

In my opinion, if we negate B)->
Cultural difference can counts for personality difference->horoscope doesn't 100% determine personality difference because culture is also deterministic.

Not assumption ->Not Conclusion

Could you address my confusion?

[zjce]

After reading the earlier posts again and again, I find out

Negating B)->Cultural Difference can explain personality difference --> Cultural is a part of personality determination --> horoscope do not 100% determine the personality only if they have same horoscope.

So in this sense, you guys are absolutely right that this requirement B) is out of scope, regardless it exists or not, does not affect conclusion

My brain must be sick. Actually go back to the Negation of B)
Cultural is a part of personality determination --> horoscope do not 100% determine the personality
The negation of assumption does NOT NEGATE CONCLUSION (negation of conclusion: 100% deterministic on personality)

I was trapped, sorry about the many posts

[WaltGrace1983]

Bonus Points: There's actually another assumption here that the LSAT chose not to test regarding birth records. Did you see it?

Would the assumption be that the birth records of these two particular individuals were in fact accurate? Maybe one was actually born on a different day, a day which would lead to a different horoscope.

[christine.defenbaugh]

Bonus Points: There's actually another assumption here that the LSAT chose not to test regarding birth records. Did you see it?

Would the assumption be that the birth records of these two particular individuals were in fact accurate? Maybe one was actually born on a different day, a day which would lead to a different horoscope.

Slam dunk, WaltGrace1983!

If the premise had said simply that two people WERE born at the same time in Toronto and New York, we would not question it. But since the premise says "birth records show..." the game is changed. We cannot question what the birth records themselves show, but we can question whether those records themselves are accurate. The author seems to be assuming that they are, in fact, accurate.

Nice work!

[WaltGrace1983]

I found this question during a review today...good times .

As made obvious from the discussion above, (B) is wrong. HOWEVER, I was thinking about why (B) is wrong in the general context of necessary assumption questions (or perhaps the LSAT as a whole) and I came to an interesting deduction that I think may be on to something. (B) essentially attempts to explain the premises. The argument is saying that "Personality tests revealed that the personalities...are in fact different" and (B) goes into detail about why the personalities may or may not be different.

Now it may not seem so because (B) just says "it wasn't caused by this or that!" but either way (B) seems to just explain the premises by ruling out some explanations.

Explaining the premises will NEVER affect an argument core, perhaps?

Such answers seem tempting because they often will connect a lot of good pieces of information. However, what they don't seem to connect is the premise to the conclusion. I am going to think about this idea more and maybe by the time I am done someone will tell me if I am on the right track or I just went to far.

...sometimes I feel like I go two steps forward and one step back . I just love figuring out the intricacies of this test and, unfortunately, sometimes I overstep my boundaries.

[BensonC202]

thank you all for clarification, but i am still confused about choice b)

"(B) This seems to strengthen the astrologers' claim, not the psychologist's. Crossing off 'culture' as an explanation for personality differences doesn't affect the psychologist's claim that horoscope isn't 100% responsible for personality."

In my opinion, if we negate B)->
Cultural difference can counts for personality difference->horoscope doesn't 100% determine personality difference because culture is also deterministic.

Not assumption ->Not Conclusion

Could you address my confusion?

In terms of the answer B that certain traits of personalities couldn't be determined by cultural factors, it does not really relevant to the arguments.

Argument is : Different geographical factor between a twins with different personalities serves as the support for the psychologist to extrapolate horoscope does not 100% determine the personalities.

Let's do not negate the option B, and think the example as follows first

" The same diet does not completely determine people's body fat percentage, since 2 people, with the same routines in life, the same groceries purchase, but not sharing the same amount of the work out times, do have different body fat percentage. "

Answer B could be paralleled as - " Body fat percentage of 2 people could not be determined by the different genres of the musics they listen to while working out.

Based on the option B, we can only infer that the issue of listening to different genres of music does not impact the issue of body fat percentage; however, by no chance can we infer any relationship between the statements of " listening to different genres of music while working out leading to different body fat percentage and the argument of sparing different times for working out leading to different body fat percentage, so same diet does not completely impact the body fat percentage.

Let's negate it = Body fat percentages of 2 people could actually be determined by the different genres of the music while working out.

It does not really damage the argument that different amount of the working out times of 2 people could lead to different body fat percentages, so same diet does not guarantee the same body fat percentage. Nor does it prove / disapprove the argument either. We only know there might be one more concept that lead to different body fat percentage.

Answer C could be paralleled as - " The diet habits of 2 people would not be changed and modified by the different working out time "

Obviously, after negating it, we have the answer as - the diet habits of 2 people would be changed or be modified by the different amount of the working out time. Then we know, it's not because of the characteristic of different the amount of the times for working out to make 2 people showing different body fat percentages but because that characteristic would make those 2 people diet different. If that's the case, the original argument be overturned.

So let us go back to the original question answer c - different geographical factors do not alter the horoscopes of 2 people. If it does, then we know that psychologist's argument be damaged and overturned.

If horoscopes of 2 be altered, then it must be true that, potentially speaking, the different personalities could be resulting from different horoscopes, and If A Horoscope could lead to A personality and B horoscope could lead to B personality, we can not exclude the possibility that both A always leads to A and B does, too. Thus, if that possibility exists, then we know psychologist's claim will not be perfect.

please let me know if I committed any reasoning errors above.