Cause and effect

[berrysugar]

In LR bible, I read that in lsats, unlike in reality, if a cause is provided, it can be considered as an ONLY cause of the mentioned effect. And I am really confused with this.
For example,
"The school principal insisted that student failures are caused by bad teaching."
Can I safely conclude that bad teaching is the only cause of student failures?
Or am I supposed to conclude that The school principal thinks that bad teaching is the only cause of student failures?

Also, as it is supposed to be the only cause, if A is mentioned as a cause of B, does that mean A is a necessary assumption for B?

Thank you.

[Luke Haqq]

Hi berrysugar!

"The school principal insisted that student failures are caused by bad teaching."
Can I safely conclude that bad teaching is the only cause of student failures?

This would depend on context. In general, yes, it's safe to take the stimulus on its face, so if it says A causes B, then that is the only causal relationship you can know to be true unless more information is given. But it's also worth noting that you might confront flaw in the reasoning question types, and a flaw could potentially be that a given stimulus, for example, doesn't consider alternative possible causes.

Or am I supposed to conclude that The school principal thinks that bad teaching is the only cause of student failures?

Again this depends on context. It's possible that the material in quotes might come within a flawed stimulus. So be on guard for identifying whether the reasoning being offered is valid or not, and also look to the question stem, which will tell you when a stimulus is flawed. If it is flawed, the principal might be in error for failing to consider alternative causes. Similarly, on a weaken question, the right answer might weaken a given causal relationship by showing an alternative cause, or showing the causal relationship is reversed.

Also, as it is supposed to be the only cause, if A is mentioned as a cause of B, does that mean A is a necessary assumption for B?

I wouldn't say this is the case. If A is the cause of B, that doesn't necessarily mean that A is an assumption.

[LanceAJ]

Are you talking about ContraPositive? Reverse & Negate

[Adam Tyson]

Contrapositives are an aspect of Conditional Reasoning, LanceAJ, not Causal Reasoning. These two types of reasoning are both common in the LR section, and the test makers will often try to confuse us in the answer choices by swapping one for another; for example, the stimulus has a conditional flaw, and a wrong answer sounds really close but throws in some causal language. It's important to distinguish the two, both in your analysis of the stimulus and in your reading of each answer choice.