▶ Your Answer :
The reading passage covers three major
points concerning the several explanations of decreasing human brain size. The
listening, however, clearly states why these points are debatable.
The first point made by the author is that
a change in human societies caused the decline in brain size. However, the
speaker challenges this by mentioning that a new kind of intelligence emerged
as the societies had developed. For example, relationship with people requires
more capacity of human brain. Hence, social changes can not account for small
brain.
Another point made by the writer is that
smaller body size, compared to that of primitives, corresponds to the small
brain size. On the contrary, the lecturer asserts that this is not true due to
the fact that fossil records show that speed of shrinking size of human body
was much faster than that of brain size. If the writer’s point is true, the
rates must be similar. Thus, the decreasing body size might not be a persuasive
reason to support the nowadays small brain size.
Lastly, the reading claims that a shirking
visual cortex is a reason of decreasing brain size. The professor debunks this
by saying that the cortex is not a primary reason because it takes only small
part in the human brain. Even if its size is decreased, it has a little effect
in the size of brain. Therefore, decreasing the size of visual cortex can not
be the main reason that the size of brain has decreased. |