#17 - Humankind would not have survived, as it clearly has

[James Finch]

Hi akanshalsat,

The stimulus proceeds by giving us a conditional statement (B A), with A being obviously true, then proceeds to say that B is a form of C (B C), concluding by logical inference that A C. (A being "human survival," B being "sacrifice," and C being "altruism")

Answer choice (A) follows this same structure:

Increased Study Time Grades Raised

contrapositive being

Grades Raised Increased Study Time

then gives us

Increased Study Time Good Time Management

After telling us that some grades are raised, thus giving us the A condition, it then concludes that there is some good time management, because we can infer A C from the same A B C setup as we had in the stimulus.

Hope this clears things up!

[captwentworth]

1. I have a question related to the diagramming of "Sacrifice Altruism"

Initially, I did not recognize that "A is a form of B" can be diagrammed as a conditional statement "A B"

After giving some thoughts, here's one way I came to think of it: I thought of it in terms of a Venn Diagram, where A is a small circle inside a larger circle B (because A is a part of B). This led me to diagram "A B" where every A is B.

Could you confirm if this makes sense/if this is a logically valid reason for diagramming "A is a form of B" as "A B"?

Even if so, I'm afraid that drawing Venn Diagrams won't always work and that I might not be able to quickly identify/diagram other variations of a conditional statement that aren't in the traditional conditional format (e.g., statements that aren't in the "if A, then B" format or that do not include key words, such as "unless" or "requires"). This leads me to my next question -

2. Would you have any advice/tips for quickly identifying conditional statements that aren't in the traditional conditional format (e.g., "A is a form of B")? Or should I try to go through a similar thought process as to what I have done above?

[Dana D]

Hey Capt,

I wouldn't think of conditional reasoning in terms of a Venn Diagram, but rather in terms of two sets of conditions.

Sufficient conditions always tell us more information because when we meet this requirement, we know we also will meet the necessary requirements.

In this example, we know that people sacrificing themselves for their kids is a sufficient condition, and that this sacrifice is also a form of altruism.

Anytime we see a sacrifice like that also know we are seeing altruism - this can be represented as Sacrifice Altruism.

If we are told that something was Altruistic on it's own, we couldn't say with certainty that this thing also involved sacrifice - no further information is generated by just being given a necessary condition.

You can apply this method of thinking to other stimuli on the test. In this example, your thinking "A is a form of B" is not incorrect, but we don't want to get in the habit of thinking that all sufficient conditions are parts or subsets of larger ideas because that is not always the case.

Hope this helped!

[Dancingbambarina]

You're trying too hard to put every aspect of this argument into the conditional chain, lathlee. Relax, let it come more naturally! Yes, that "when doing so" statement has conditional elements, and they go something like this:

Sacrific Self Chidren Survive

This is because "doing so" refers to sacrificing oneself, and "ensuring" is a necessary condition indicator.

Having done this, where did it get us? Not far. We learn that there are some instances where sacrificing oneself ensures the survival of your children. Is survival of children sufficient for something else here? No. Is something else sufficient for sacrificing oneself? Sort of, yes - we would not have survived as a species if that did not happen, or:

Sacrifice Self Species Survives

So the contrapositive gives us:

Species Survived Sacrifice Self Children Survive

That's kind of a tautology, a self-proving statement, because it's really just saying that we, the descendants of our ancestors, have survived, proving that our ancestors did stuff to ensure that we survived, which means we survived. Not very helpful to chase this down, is it?

Your diagram appears to be stringing together some things that are conditional with others that are not, simply because they appear in the sentence in a certain order. If I were to read your diagram as a sentence, it would be:

"If our ancestors sometimes sacrificed themselves, then they were not motivated to do so, then we would not have survived, which would then prove no altruism."

Forget the order of the terms, lathlee, and focus on the logical relationships. What are the statements that you can paraphrase in "if...then" form? If our ancestors had not been motivated to sacrifice themselves, then what? If we survived as a species, then what?

One final note, and that is that you said you agreed that the correct answer was the best match, but you still hesitated. Don't do that! When you know an answer is the best match for what you need it to be, even if you do not understand it, do not hesitate, but select that answer with confidence and a light heart, knowing that you are moving on to more questions and more correct answers! That's how you win at this test. He who hesitates is lost!

Re-read the official explanation here, and if needed then read Kelsey's excellent breakdown, to see the right way to tackle the conditional relationships here. Don't just blindly string words and phrases together based on word order, but base those diagrams on logical relationships (and paraphrasing in if...then form when you need to in order to understand them).

Good luck!

The "Some children" in AC A made me think for a second, as there isn't a corresponding "some" in the conditional trigger in the stimulus.

However, I note that this some isn't a formal logic "some", but is indeed just saying that some of these children triggered the conditional.

Thanks very much