#16 - Stress is a common cause of blood pressure

[Adam Tyson]

"Most" does not imply either a sufficient condition or a necessary one, nor does it imply a cause or an effect, SGD2021. There is nothing automatic about where it belongs in a diagrammed relationship, and you have to analyze the author's meaning to determine what is sufficient or necessary and what is a cause and what is an effect.

In this case, the author is saying that most people can calm their minds by exercising. "Calm their minds" is an active, causal relationship - doing one thing (exercising) causes another thing (a calm mind). The "most" just means this is true for more than half of all people. It doesn't apply to most exercise, nor does it have anything to do with how calm one becomes. It's just another way of saying that this is usually the case; more than half of all people can bring about this effect by engaging in this cause.

It's understandable to want to find absolute rules about the LSAT that can be reliably applied to all uses of a certain word or phrase or construction, but the test usually isn't that simple. You have to think about what the author intends in the way they crafted their argument, and how the words and phrases they choose relate to each other and support their claims. As soon as you try to nail down an absolute rule, like "most goes on the left side," you are bound to find many exceptions that frustrate that process! Instead of looking for absolute rules like that, look for concepts and relationships and patterns. Be flexible, and be prepared for them to shake things up and do things differently!

[SGD2021]

Thank you very much! So in this case, since we're saying that "most" people who exercise can calm their minds, that is why we drew it this way: E CM ? (as opposed to saying "most who can calm their minds exercise" which wouldn't necessarily be the case). So it can help to say the statement backwards when determining how to diagram.

Additionally, with "most" statements, is it always possible to draw the following conclusion or is this another thing we should avoid making a general rule for? Example: A--> (m above the arrow for most) B. The conclusion is that, since most of A is B, then some of B is A, always?

[Adam Tyson]

Looks like you've got it! The diagram A B can be read as "most As are Bs", and if that is true then it must also be true that some Bs are As. The "some" can go backwards, but the "most" cannot.

[LSATtaker23]

I originally chose D instead of E for this question, and understand why the word, "directly", makes it incorrect, but still have some reservations about E. If "most" people can calm their minds by exercising, and "some" people can lower their blood pressure by calming their minds, that could mean that 60% of people can calm their minds by exercising, while 10% of people can reduce blood pressure by calming their minds. If that were the case, there is not guarantee of overlap between those two populations.

So, I felt that D, because it said exercise "can" lower blood pressure, rather than making a guarantee that the statement was true for some people, was more strongly supported. If this were a "must be true" question, would I be correct in saying that E is not necessarily true?

[Rachael Wilkenfeld]

LSATtaker, answer choice (E) IS necessarily true.

Let's look at the relationship in the stimulus. Most people can calm their minds by engaging in exercise. That means that some of the people who engage in exercise calm their minds. We know that calming your mind reduces stress. So now we can say that some people who engage in exercise can reduce their stress. Which people? Those exercisers who can calm their minds by engaging in exercise.

You appear to be trying to go further---linking these ideas and chains to lowering blood pressure. We can't quite do that here. Answer choice (E) doesn't require us to. It just needs to link engaging in exercise with lowering stress. We only need one person who engages in exercise to have lower stress for answer choice (E) to have to be true.

Hope that helps!

[RickyLW]

Hello - would diagramming the stimulus using FL be a valid way of solving this problem? I did so and produced the following chain:

Exercise Calm Mind Reduce Stress Lower Blood Pressure

The problem I had with this chain is that it allows you to infer that "Lower Blood Pressure Reduce Stress," which is the reverse of the causal relationship in the stimulus. This leads me to believe that these kinds of CE questions are not compatible with FL. However, given the use of "some" and "most" in the stimulus, I am unsure how else you would solve them. I would appreciate any guidance.

[Jeff Wren]

Hi Ricky.

This question can be tricky in that it involves both causal reasoning and formal logic terms.

You diagramed the stimulus:

Exercise Calm Mind Reduce Stress Lower Blood Pressure

The difficult part is understanding what your diagram means in plain English and not misreading/misunderstanding the meaning.

For example, the first part of your diagram might be read to mean "most people who exercise calm their mind or "most people who exercise have a calm mind." Neither of these is quite right. What the stimulus actually says is that "most people can calm their minds, in turn, by engaging in exercise."

I'd diagram this:

People Can Calm Mind by Exercise

Notice that the stimulus doesn't say that most people do calm their mind by exercise, just that they have the ability to do so. And while the connection between exercise and calm mind is causal, separating the terms out can actually make the diagram more confusing.

Since calming one's mind does "thereby reduce stress" this does allow a full causal arrow between:

Can Calm Mind by Exercise Can Reduce Stress

Linking the two diagrams together gives us:

People Can Calm Mind by Exercise Can Reduce Stress

This is enough to prove Answer E.

As for the final part of your diagram:

Reduce Stress Lower Blood Pressure

This is where you may be misreading/misinterpreting what this diagram means compared to what the stimulus says.

What the stimulus says is basically that some people can lower their blood pressure by calming their mind/reducing stress.

Perhaps a more helpful diagram to convey this this would be:

People who Can Calm Mind by Exercise (and Can Reduce Stress) People who Can Lower Blood Pressure

The idea is that there are some people who can calm their mind by exercise (and can reduce stress) who can also lower their blood pressure. This part of the some statement is reversible, in that there are some people who can lower their blood pressure who can also calm their mind by exercise (and can reduce stress).

However, this does not mean that the causal chain itself is reversible. That would an incorrect interpretation of what is being stated in the stimulus.

[RickyLW]

Hi Jeff - thank you very much for the detailed explanation. You've cleared this question up for me.