Generally, of any two animal species, the species whose

Question

Generally, of any two animal species, the species whose ratio of brain mass to body mass is greater will be the more intelligent. However, it has been established that many great mathematicians have brains considerably smaller, relative to their bodies, than the average human. This indicates that while the ratio of brain mass to body mass is a reliable indication of intelligence across species, this is not so within species.

Which one of the following is an assumption required by the argument?

(A) The ratio of brain mass to body mass is the most reliable indicator of intelligence across animal species.
(B) There are no salient physiological differences between members within a species that reliably indicate which member is the more intelligent.
(C) There are some great mathematicians with a relatively low ratio of brain mass to body mass who are more intelligent than the average human.
(D) The ratio of brain mass to body mass in humans is in no way correlated with mathematical ability.
(E) The ratio of brain mass to body mass within animal species tends not to vary greatly.

Tiffsootmoot8 · Answer

The argument no where tells that great mathematicians are more intelligent than an average human. Without this assumption true, the argument collapses.
Hence C is the correct answer

Vivek1707 · Answer

Notice the  GAP  in the argument

The argument makes a statement about  mathematicians  and their brain to body ratio in comparison to average humans ---> then  jumps  on to a conclusion about  INTELLIGENCE

*** Is being good at math always = intelligence ?  Don't assume  unless the argument provides support !!! An assumption will essentially fill this GAP.

A -  Negation :  The ratio of brain mass to body mass  is   NOT   is  the most reliable indicator of intelligence across animal species . The argument still stands. The argument never says that that the brain to body ratio is the most reliable indicator. Eliminate.

B Salient physiological differences are  out of scope . The argument is concerned about brain to body ratio and its link to intelligence. There can be other salient physiological differences but that does'nt affect the argument.

C  Correct . This fills the GAP. If you  negate  this choice.  There are  some   No  great mathematicians with a relatively low ratio of brain mass to body mass who are more intelligent than the average human . This would imply that the brian to body mass  is  an indication of low intelligence. The  conclusion  that brain to body mass  is not a  good indicator of intelligence within species  crumbles.

D If you negate this choice " The ratio of brain mass to body mass in humans is   in no way   correlated with mathematical ability ."  So what  ? Does this help with the conclusion that brain to body mass is an indicator intelligence across and not within species ? NOPE, Eliminate.

E  Negation :  The ratio of brain mass to body mass within animal species  DOES  tends not to vary greatly . Again no impact on the conclusion.

sansun · Answer

C is the correct one because it is the most suitable hidden assumption.
 
To use mathematicians as a counterexample, the argument must assume that these mathematicians are more intelligent than the average human, despite having a lower ratio.

Generally, of any two animal species, the species whose

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Generally, of any two animal species, the species whose

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