The ability of mammals to control their internal body temperatures is a factor in the development of their brains and...

Alyona1983 on February 7, 2020

Is this a cause-and-effect question?

AndreaK on February 7, 2020

Hi @Alyona1983,

This is a necessary assumption question. Our goal is to bring to light the missing piece of information that the conclusion relies on in order for it to be possible.

The conclusion we are seeking a necessary assumption for is:

"The ability of mammals to control their internal body temperatures is a factor in the development of their brains and intelligence."

So we want to be thinking to ourselves, what piece of information in the answer choices is necessary to be able to draw this conclusion? (Remember, we're just looking for something that's necessary to draw it, not something that's sufficient to guarantee it.)

Our correct answer, D, gets at that necessary assumption by bringing to light a gap in the argument. It states:
"The development of intelligence in animals is not independent of the chemical reactions in their brains taking place at the proper temperatures."

We can use the negation technique to test this. What if it were the case that the development of intelligence was independent of the chemical reactions taking place in their brains at the proper temperatures? Well, that would be problematic for the last part of the conclusion. Because then, how is the evidence supposed to support the part of the conclusion that says "The ability of mammals to control their internal body temperatures is a factor in the development of their brains AND INTELLIGENCE."

Hopefully that helps you better see why answer choice D provides some necessary information that you would need to be able to draw the conclusion at hand. Let's take a look at answer choice C now and compare.

C: The brain cannot support intelligence if the chemical reactions within it are subject to uncontrolled temperatures.

The problem with C is that our argument's conclusion discusses temperature regulation as a factor that contributes to the DEVELOPMENT of intelligence. However, SUPPORTING intelligence, as discussed in C, is a different function. Though that may seem like a subtle distinction, those are actually two different things. Being a factor that contributes to development is not at the same bar as a temperature regulation being necessary to supporting intelligence.

Hope this helps, this is a tricky question!

Alyona1983 on February 8, 2020

Dear Andrea, thank you so much for the detailed explanation. I clearly see now why C is wrong. With D it was mostly my confusion with wording "is a factor" and "not independent".
Thank you for help!

AndreaK on February 8, 2020

Hi @Alyona1983,

Great to hear, happy to help! :)