Doubt in causation

Grey Warden

Hey, I was wondering that when we say that A causes B, do we understand it to mean that whenever A will happen B shall follow or does such a causal relationship accommodates some instances wherein A happens but then B does not follow. I had trouble with question 11 in LR Section 1 on PT 58 and I think it was because I wasn't clear on my understanding of causation.
https://7sage.com/lsat_explanations/lsat-58-section-1-question-11

runiggyrun

No, A causes B doesn't mean every instance of A causes B. Kids playing with matches cause fires, but not every child playing with matches will set the house on fire. However, the LSAT won't test on the distinction between "A can cause B" and "A causes B every time". That's too messy of a distinction and the LSAT likes clear cut things. This question certainly doesn't as the conclusion is phrased as "there's no causal connection" not "doesn't cause". "Causal connection" is a softened version of "causes" and acknowledges that there might be other factors that influence the outcome (there's a causal connection between smoking and lung cancer, but there are smokers who don't get lung cancer, so other things need to cooperate with smoking to lead to development of cancer)

This is a very tricky question for a couple of reasons:
Most of the time the LSAT arguments say there's a causation relationship when that's not necessarily true. All you have to do is show that something else could explain the observed correlation. This argument is saying that there isn't a causation relationship and you have to show that there might be one. That's very unusual for the LSAT.

The way I thought about the flaw was to think that you need something else in addition to chromosome damage to get schizophrenia, and that's why not everybody with the damage gets it (maybe you have to be male and have the damage to develop schizophrenia). The damage still causes it, but not every time.
I'd venture a guess that most people would think about the flaw in a similar way.
However, the correct answer goes a different way and states "not all kinds of damage to chromosome 6 cause schizophrenia". (Maybe chromosomal deletions do, but chromosomal insertions don't). That would explain why when you lump the two together as "damage" some people show the effect and some don't. So THERE IS a causal relationship, but it's between a certain kind of damage and schizophrenia. Certainly a surprise answer for me.

Then there's the confounding matter of "some people get schizophrenia without the damage" which appears to be part of the argument that there's no causal correlation. This is extraneous information, as there are tons of very valid causal relationships where the effect can happen without that specific cause.
Ingesting 100g of potassium cyanide causes death (and that's one of those "causes death" without a lot of ifs and buts). There are tons of people who die without ingesting 100g of potassium cyanide. Which is of course, irrelevant to the fact that cyanide does in fact cause death. Just like the fact that you can get schizophrenia without chromosome 6 damage. The only thing this premise does is to lead us nicely the into trap answer B "assumes that all schizophrenia is caused by chromosomal damage".
B is a very tempting answer especially because we're so used to taking apart causation arguments - however, out author is clearly stating that "there is no causal correlation", so clearly he doesn't assume schizophrenia is caused by chromosomal damage. Quite the opposite.

I'd say this is one of the trickiest LSAT questions I've seen in a long time.

LSATisland

@"Grey Warden" Technically, A causes B should mean always. Otherwise, it should be qualified as A "can" cause B or A "sometimes" causes B. In everyday jargon, we understand that "kids playing with matches cause fires" as a potentiality, but that is in virtue of our knowledge qualifying an unqualified statement.

The stimulus mentions a correlation between the damage and schizophrenia. After citing some instances where the damage did not cause schizophrenia, the stimulus concludes that there is no causal connection between the two. However, this is false, as it is possible that damage is part of the cause for schizophrenia or is the sole cause under the right conditions = hence a causal connection.

Grey Warden

Awesome, this is super helpful guys. Thank you so much for clarifying @runiggyrun @LSATisland