Humankind would not have survived, as it clearly has, if our ancestors had not been motivated by the desire to sacrif...

shunhe on August 7, 2020

Hi @izzy,

Thanks for the question! So first, I’ll diagram the stimulus. First, we’re told that humankind wouldn’t have survived (as it has) if our ancestors hadn’t been motivated by the desire to sacrifice themselves when doing so would ensure the survival of their children or other close relatives. OK this is kind of a long premise, but basically

~Ancestors have sacrificial desires in certain cases —> ~Humankind survived

And the separate premise

Humankind survived.

Then we’re told that this kind of sacrifice is a form of altruism. So

Sacrificial desires in certain cases —> Altruism

We then conclude that our ancestors were at least partially altruistic. And that makes sense, since if we take the contrapositive of the first conditional

HS —> ASDCC

And we know humankind survived, so we can get ASDCC, and we know that was altruism. So the ancestors did altruistic things.

Now we’re asked for a parallel argument. (D) says something like

~Replaced by alternative —> Natural resources depleted
Replaced by alternative generally requires more power
Conclusion: Natural resources depleted

And this doesn’t really match what’s above. (A), on the other hand, does. It tells us

~Increase study time —> ~Raise grades
Increase study time —> Good time management
Raise grades (for some students)
Conclusion: Manage time well (for some students)

And that parallels the reasoning above.

Hope this helps! Feel free to ask any other questions that you might have.

izzy on August 10, 2020

That makes sense. Thank you!