Music For The Masses
by Melissa Manhas
Many people believe that, from an
evolutionary perspective, music
serves no apparent useful purpose.
Recently, researchers have begun
to explore the potential reasons for
the robust musical capacity that humans
have. It is thought that maternal
music is important for motherinfant
interactions and bonding.
It is also thought that our closest
animal relatives have some musicrelated
traits that we humans possess,
even though they do not have
the same capacity for music that we
have.
After being dragged out of bed
at three o’clock in the morning by a
crying baby, one of the first things
a mother does is pick the infant up
and sing a soothing lullaby. These
slow, repetitive songs are unique to
humans and are used by mothers of
every culture, often to pacify crying
or fussy infants. In one study,
infants were perceived to be happier
when listening to lullabies than
when listening to “adult” music.
For simian primates, infant crying
is minimal because the mother
is almost always carrying the baby.
This constant contact allows the
mother to quickly detect any discomfort
and address the problem
almost immediately. Indeed, the
only reliable way to make a primate
infant cry in a laboratory setting
is to physically separate it from its
mother. In the wild, this outcry
would be an essential trait because
an infant that becomes lost or falls
off its mother’s back would be able
to alert its mother and be retrieved.
From an evolutionary perspective,
a howling human infant could
be detrimental to all those around
it, especially in hunter-gatherer
societies. A noise could alert prey
to the presence of people, leading
to an unsuccessful hunt. Likewise,
the group would be exposed to any
nearby predators that would be
alerted to their presence and position.
For these reasons, a reliable
way to quell crying would be advantageous.
Conversely, child-directed play
songs can also be used to rouse infants.
Studies have shown that when
infants view a video of their mothers
singing, they watch and are engaged
for much longer than when
watching a video of their mother
simply speaking.
Interestingly, maternal singing
can either increase or decrease
activity depending on the infant’s
stress levels. In one study, saliva
samples of infants were collected
and cortisol levels were measured.
Cortisol is a stress hormone; high
levels are associated with high stress
and low levels with low stress. This
study found that maternal singing
can be used to decrease stress and
induce sleep in infants, but also to
increase stress in order to gain an
infant’s attention and to awaken it.
Throughout the day, singing can be
used as a tool by a mother to promote
homeostasis—the equilibrium
of metabolic processes—in her
infant.
The vast capacity for music that
humans possess is unique, but music
is not exclusive to humans. The
most obvious example of music in
the animal kingdom is that of birds,
but it also occurs with other animals,
such as dolphins and whales.
After humans, many would consider
birds to be the most musical
organism. Songbirds learn to sing
by hearing the songs of other members
of their species. When exposed
to bird songs of their own species
and to those of other species, young
birds learn their own species’ songs
exclusively. This indicates that they
have an innate ability to recognize
and learn these specific songs. If
songbirds are not exposed to the
typical songs of their own species
they will still sing, but only simple,
unusual songs that other individuals
may not recognize. This need for
learning is seen in humans as well.
Surprisingly, it is not seen in monkeys
or apes, our closest relatives;
however, they do share some musical
capabilities with us.
The fact that humans share some
musical capabilities with primates
is demonstrated in one experiment
where rhesus monkeys were played
two types of short melodies; a basic
melody and a transposed melody.
These transposed melodies were the
same as the original melodies, except
that the pitch was increased or
decreased. The monkeys considered
two melodies as
being the same
when they were
transposed by
one or two octaves
(an octave
being the interval
between
one pitch). Humans
also judge
such melodies
to be the same.
This study suggests
that since
monkeys do not
produce music
themselves,
the musical
sensitivity they
displayed may
indicate that
some characteristics
of musical
perception
originate from the auditory system.
Furthermore, previous studies
have shown that birds are not able
to identify melody transposition.
This implies that this ability did not
evolve until some time after the divergence
of birds and mammals.
While monkeys are similar to
humans in that they are able to
identify the similarities between
melodies played at different octaves,
they do not have the same
capacity for music in all regards. In
one study, musical selections with
consonant (harmonious) or dissonant
(jarring) intervals were played
to tamarins, a type of monkey. The
study found that tamarins had no
preference for either consonance or
dissonance. Humans, on the other
hand, showed a strong preference
for consonant intervals.
Not only do monkeys lack the
ability to differentiate between
some musical qualities that humans
are able to distinguish, but their affinity
for music is also much lower.
In one study, the responses of cotton-
top tamarins and marmosets to
music tempo were examined. In one
part of the study, the animals had a
choice between lullabies or techno
music. In the case of both the tamarins
and marmosets, there was a
strong preference for lullabies over
techno music. Another experiment
was then done to see if the animals
actually enjoyed the slow tempo
music, or if they simply chose the
lesser of the two evils. It was found
that both the tamarins and marmosets
had a strong preference for
silence over the lullabies. Humans
in the study did not have much of a
preference in tempo; however, they
preferred music over silence.
Interestingly, one researcher has
found that playing hard rock songs
by Metallica and Tool (considered
human fear/threat-based music) to
tamarins elicited a response; ironically,
it calmed them down. An experiment
was then carried out to
see if tamarins respond to music
designed specifically to duplicate
their calls. Compared to human
music, the customized music elicited
a much greater response in
the tamarins. From this study we
might infer that since monkeys do
respond to some types of musical
sounds, that they may have similar
fundamental musical systems to
humans. Since there are some differences
in musical preferences and
capacities between primates and
humans, we might surmise that in
our evolutionary history, natural
selection caused these systems to
diverge and to develop in a unique
manner in humans.