Cause and effect relationships were probably one of the argument structures that you were most comfortable with before starting your LSAT prep. You see A happen…A is followed be B…so you know that A caused B.
But as much as I hate to shatter this appealingly simple worldview, you’re going to find with the LSAT that cause and effect relationships usually make for weak arguments. Causal arguments are almost always flawed because they don’t rule out other possible explanations for a given phenomenon.
That is why you often see cause and effect pop up in the stimuli of Strengthen and Weaken questions. On a Strengthen question with a cause and effect relationship present, the correct answer choice will often act as an additional premise which helps to rule out alternative causes. Whereas, on a Weaken question with a cause and effect relationship, the correct answer will often act as an additional premise which opens up other possible explanations for the phenomenon described in the argument.
Let’s take a look at how this works.
What if I told you that LSAT students who exclusively drink green tea have higher average scores on the LSAT? Would you be running down to your local Costco to buy a crate of tea bags to give you that edge on your exam? Before you make that purchase, first think back to cause and effect arguments on the LSAT. If there is a correlation between high volume green tea consumption and LSAT performance, does that necessarily mean that the tea causes the high score?
No, it does not. Maybe only the most disciplined and patient people are willing to take the time to brew cup after cup of green tea, and these qualities also make them more likely to put in long hours of quality LSAT study. Or maybe it’s simply the case that exclusively imbibing green tea rules out the possibility that the drinker is over-consuming on the kind of adult drinks that would hamper their LSAT studies.
This means, if you see a correlation between green tea and LSAT performance in the stimulus of a Weaken question, the argument is weakened by an answer choice that offers up one of these other plausible explanations for the correlation. On some questions, it could also be weakened by an answer choice which showed that the cause and effect relationship did not hold in a similar situation.
On the other hand, if you are dealing with a Strengthen question about green tea and the LSAT, a correct answer choice would rule out some of the alternative explanations for the correlation, or simply lend support for the cause and effect relationship. Something like “green tea drinkers do not show any other distinctive characteristics which aid their exam preparations” would rule out the possibility that green tea drinkers happen to be good test takers because of some other shared characteristic.
Now that you know what to look for in the answer choices of Strengthen and Weaken questions with causal reasoning, let’s discuss how to spot a cause and effect relationship in the stimulus in the first place
1. Indicator Words
Certain words or phrases can help you to easily identify a cause and effect relationship, including: causes, results in, leads to, produces, contributes to, due to, leads to, and responsible for. For example, in the statement “A low LSAT score results in premature baldness,” the phrase “results in” indicate a cause and effect relationship.
Cause and effect relationships may also be present in an argument as a way to explain a phenomenon. For this type, look out for a phenomenon (premise) paired with a way to explain that phenomenon (conclusion). For example: “Chris looked terrible the morning of the LSAT. It must be because he had very little sleep the night before.” Here, the phenomenon is that Chris looks terrible, and the explanation given is a lack of sleep. Therefore, a lack of a sleep called Chris’s off-putting visage.
3. Prescriptive Statements
A prescriptive statement is simply an expression of what one “should do” or “ought to do.” These also qualify as cause and effect relationships, because the conclusion is based on the assumption that you can control the effect by controlling the cause. For instance, “Everyone who goes to Harvard Law School owns snow boots. So if you want to get into Harvard, you should go out and buy snow boots.”
Identifying cause and effect relationships is a key part of mastering the Strengthen and Weaken questions on the LSAT, but they can also be found on other types of Logical Reasoning questions, as well as the Reading Comp section. That’s why learning to identify such arguments on the exam and predict their associated correct answers is such an essential part of realizing your LSAT goals.