Since the dawn of time, humans and
non-human animals have shared the earth with one another. However, we did not
always have the same relationship with animals that we have today. All animals
were once wild animals to us, and the only interactions we had with them
involved hunting or being hunted. It took us thousands of years to domesticate
animals to use for food and companionship, and many factors to determine which
animals were able to be successfully domesticated.
There is a bond that emotionally connects
us to our companion animals known as the human-animal bond, or HAB for short.
As was discussed in Meg Daley’s TED talk, the HAB is heavily influenced by oxytocin.
Oxytocin is known as the bonding hormone, and is largely responsible for
connections between mother and infant. It also plays a role in most other
relationships. Oxytocin is present in high levels in social species, and it
lowers adrenaline levels so that members of the same or different social
species will not be in constant fear of one another. Because of this, primitive
humans were able to have some level of interaction with other social species
such as lions or wolves. The domesticated dogs that we have in our homes today
exist because humans were able to interact with less aggressive wolves closely
enough to eventually come into possession of wolf pups by one method or
another. When these wolf pups were hungry, human women fed them the only way
they knew how; suckling them. This caused oxytocin release in both the human
women and the wolf pups, most likely leading to the earliest HABs. Humans
eventually bred many generations of the tamest wolves to create the many
species of domesticated dog that we have today. As was discussed in lecture, oxytocin
is released in both human and dog when a dog is pet and it is also release in
both parties when looking into one another’s eyes. Oxytocin release causes a
feel-good reaction that rewards both the dog and the human for these
interactions. The HAB is stronger than ever today between owners and pets
because of the same hormone that first assisted us in the domestication of
wolves.
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Belyaev with a fox. Examples of domesticated coat color, upper left. |
One quality that humans seem to
select very highly for in domesticated companion animals is cuteness. We like
companion animals that have qualities that we see as infantile, and we like
them to retain many of the characteristics that they have as juveniles. The
retention of juvenile physical and behavioral characteristics into adulthood is
known as neotany, and much of the breeding that we do with companion animals
selects highly for this trait. We enjoy pets that stay playful their whole
lives with traits like large eyes, and soft, rounded features. These characteristics
trigger a protective and nurturing response in humans because they remind us of
our own infants. They also activate a key reward center in the brain, the
nucleus accumbens. We are hardwired to enjoy traits like these because it helps
to ensure the survival of human infants. Man's
new best friend? A forgotten Russian experiment in fox domestication
discusses the experiments of Dmitri K. Belyaev in domesticating silver foxes.
By selecting the tamest foxes from each generation he bred, he was ultimately
able to breed foxes that enjoyed human interaction in much the same way dogs
do. They had lower adrenaline levels than wild foxes along with altered coat
coloration, and Belyaev hypothesized that the pathways for adrenaline and
melanin were connected. This was later confirmed. Along with this change, these
foxes had more neonatal characteristics than their wild counterparts such as licking
their caretakers, staying playful longer, and altered skull shape. By breeding
only the tamest animals when we first began to domesticate them, we most likely
inadvertently created more neotany with each generation and grew more attached
as a result.

As was discussed early on in the
video, one of our first main reasons for wanting to domesticate animals was so
that we could eat the same way we saw the top predators were eating. It was
also mentioned that there was a point at which humans were afraid of even large
herbivores because it is much more difficult to approach a wild animal than a
domesticated one. We eventually domesticated these large herbivores and they
would eventually be bred to become the modern horse and cow. However, attempts
to domesticate similar large herbivores such as the zebra have been
unsuccessful. Jarod Diamond suggests that all species that could possibly be
domesticated share six traits: flexible diet, fast growth rate, pleasant disposition,
the ability to breed in captivity, a social hierarchy, and no panic. When it
comes to diet, herbivore diets have always been cheaper and easier to provide
meaning that herbivores were fairly easy to feed in captivity. Carnivores had
to be able to scavenge or hunt when humans couldn’t necessarily provide meat regularly,
so cat and dog ancestors were able to take care of their own dietary needs
pretty well. Almost all domesticated species reach sexual maturity within a
matter of a couple of years or less depending on the species. We have bred
animals that did not originally possess a pleasant disposition to have one now
by selecting their tamest ancestors. All domesticated animals can breed in
captivity, and many that we use for food are bred using artificial insemination
to speed up the process and make it more efficient. Even animals like chickens
have a social hierarchy, although social hierarchies are not necessarily as
complicated in animals as they are in humans. Domesticated animals that are
handled well and are not abused or neglected will generally not be panicky. These
qualities that diamond came up with are the basis for what any animal needs in
order to be domesticated, and every animal that humans have successfully
domesticated seems to possess these qualities.
There are many factors that lead to
the domestication of animals and the formation of the strong human-animal bond
between pet and owner. We are lucky to have been able to use these factors to
our advantage, and we can now enjoy food, clothes, companionship, and much more
that would have been off limits without the help of domesticated animals.