The two passages discuss recent scientific research on
music. They are adapted from two different papers
presented at a scholarly conference.
Passage A
Did music and human language originate
separately or together? Both systems use intonation
and rhythm to communicate emotions. Both can be
produced vocally or with tools, and people can produce
(5). both music and language silently to themselves.
Brain imaging studies suggest that music and
language are part of one large, vastly complicated,
neurological system for processing sound. In fact,
fewer differences than similarities exist between the
(10) neurological processing of the two. One could think of
the two activities as different radio programs that can
be broadcast over the same hardware. One noteworthy
difference, though, is that, generally speaking, people
are better at language than music. In music, anyone
(15) can listen easily enough, but most people do not
perform well, and in many cultures composition is left
to specialists. In language, by contrast, nearly
everyone actively performs and composes.
Given their shared neurological basis, it appears
(20) that music and language evolved together as brain size
increased over the course of hominid evolution. But
the primacy of language over music that we can
observe today suggests that language, not music, was
the primary function natural selection operated on.
(25) Music, it would seem, had little adaptive value of its
own, and most likely developed on the coattails of
language
Passage B
Darwin claimed that since “neither the enjoyment
nor the capacity of producing musical notes are
(30) faculties of the least [practical] use to man…they must
be ranked amongst the most mysterious with which he
is endowed.†I suggest that the enjoyment of and the
capacity to produce musical notes are faculties
of indispensable use to mothers and their infants and
(35) that it is in the emotional bonds created by the
interaction of mother and child that we can discover
the evolutionary origins of human music.
Even excluding lullabies, which parents sing to
infants, human mothers and infants under six months
(40) of age engage in ritualized, sequential behaviors,
involving vocal, facial, and bodily interactions. Using
face-to-face mother-infant interactions filmed at 24
frames per second, researchers have shown that
mothers and infants jointly construct mutually
(45) improvised interactions in which each partner tracks
the actions of the other. Such episodes last from
one-half second to three seconds and are composed of
musical elements—variations in pitch, rhythm, timbre,
volume, and tempo.
(50) What evolutionary advantage would such
behavior have? In the course of hominid evolution,
brain size increased rapidly. Contemporaneously, the
increase in bipedality caused the birth canal to narrow.
This resulted in hominid infants being born ever-more
(55) prematurely, leaving them much more helpless at birth.
This helplessness necessitated longer, better maternal
care. Under such conditions, the emotional bonds
created in the premusical mother-infant interactions we
observe in Homo sapiens today—behavior whose
(60) neurological basis essentially constitutes the capacity
to make and enjoy music—would have conferred
considerable evolutionary advantage.
Both passages were written primarily in order to
answer which one of the following questions?