Author : Wahid Ahmad
Babies naturally want to be held and carried close to their
caregivers. This instinct goes back to our earliest ancestors. While modern
societies sometimes see carrying babies as a trend, it's actually deeply rooted
in our evolutionary history. From our primate ancestors to early humans,
carrying babies has been a normal practice.
In the animal world, parents take care of their young in
different ways. One common method is nesting, where parents build nests to
protect and hide their babies while they go out to find food. Some animals
carry their babies in their mouths for short distances, while others carry them
on their bodies.
Carrying babies on the body has evolved multiple times among
different animals, including mammals. Once carrying evolved, it became a common
strategy because it provides important benefits despite the energy it requires.
Animals that carry their young tend to have smaller home ranges and face
certain reproductive costs. However, the benefits outweigh these costs.
Carrying babies requires certain physical and behavioural
adaptations between parent and infant. For example, the composition of the
mother's milk changes to accommodate frequent feeding.
It's believed that the ancestors of primates and tree shrews
didn't carry their young. The practice of carrying likely started evolving
around 55 million years ago when the first primates appeared.
Why did ancient primates start carrying their infants instead
of nesting?
One reason could be to avoid the challenges associated with
nesting, like parasites and predators. Also, carrying allows for a closer bond
between parent and offspring, which can be advantageous for both.
In essence, the switch from nesting to carrying among early
primates was likely driven by the benefits of closer parental care and the
challenges of traditional nesting methods
Apes like gibbons, orangutans, gorillas, and chimpanzees have
different methods of carrying babies. The baby holds onto the mother's fur
using its hands and feet. For the first few weeks of a newborn's life, they are
carried on the front.
Gibbons and orangutans, living in trees, carry their young on
one side for safer tree movement. For chimpanzees and gorillas, spending more
time on the ground, babies are initially supported by their mothers, later
transitioning to clinging to the mother's back. This isn't an issue for
chimpanzees due to their small babies with grasping toes.
Early hominins like Orrorin, Sahelanthropus and Ardipithecus,
considered predecessors to humans were bipedal and probably a sloped back, and carried their young on their backs after the initial front position.
The Australopithecus, lived around 2-4 million years ago and
had relatively small brains compared to modern humans. These species likely
represent the ancestors of Homo sapiens.
Australopithecus afarensis juveniles showed features
suggesting they could grasp with their feet, possibly onto their mothers. As
they grew, their feet became more adapted to bipedal walking losing the ability
to grasp as much with their toes.
Studies suggest that Australopithecus afarensis infants had a
prolonged period of brain growth, making them dependent on their caregivers for
a long time, much like humans.
Australopithecus afarensis likely carried their babies on
their front in the early weeks after birth. As the baby grew, they might have
switched to carrying them on the side or possibly on their back.
Carrying babies on the side or back, like seen in some Asian
apes, had advantages. It allowed easy access for breastfeeding, and the baby
could see what the parent was doing, promoting social interaction. This method
of carrying also supported the infant's ability to grasp onto the caregiver
while the parent was moving around.
Changes in how babies were carried might be linked to the loss
of body hair in our ancestors. Some suggest that as hominins became bipedal
they lost their body fur. This loss might have made it challenging for infants
to cling to their parents' fur, leading to a need for more manual hands-on support.
The genus Homo includes many species, but today only Homo
sapiens are around. Homo habilis, meaning "handyman," is considered
the first human-like toolmaker. They lived around 2.3 -2.4 million years ago
and it's believed they might have carried their young in a way similar to
afarensis, with an initial front position and laterally as the infant grasped
more.
Homo erectus emerged around 2-1.8 million years ago and
migrated to Asia and Europe. They had decreased body hair and an increase in
brain size. The evolution of brain size may have required a different diet,
possibly leading to better hunting and scavenging.
With the decrease in body hair and an increase in adipose
tissue, it's suggested that infants might have adapted how they clung to their
caregivers. The growing fat content of female bodies, along with the loss of
body fur, provided better surfaces for infants to be positioned on the female
hip. This likely influenced new ways of carrying infants.
Babies are born with special automatic responses, kind of like
built-in tricks, that help them hold on to their caregivers easily. These
responses are called primitive reflexes. You've probably seen it when someone
carries a baby, and the baby just naturally clings to them without much effort.
One reflex is called the Tonic Labyrinthine Reflex. It helps
the baby control their head and neck when they're not perfectly centered on
someone's shoulder. So, when the baby moves their head, their body curls in or
straightens out.
Then there's the Plantar Reflex, which makes the baby grab
onto things with their hands and feet. This is super helpful when they're being
carried, as it helps them stay stable by holding onto the caregiver's skin or
clothes.
One reflex, the Moro reflex, is like a surprise response
babies have. It might have evolved to help babies hold on to their parents when
something sudden happens. The stepping reflex is another trick babies do when
their feet touch something - it's like a little adjustment to help them cling
better.
When babies are carried on the hip, they naturally lift their
legs, making it easier for them to hold on to the caregiver.
As they get bigger, they learn to support themselves better,
but these reflexes still help them cling to their caregivers. It's like
nature's way of making sure babies stay safe and close to the people who take
care of them!
Throughout history, people have cared for infants while doing
daily tasks. Traditional carriers, like cloth and basket carriers, were likely
used to help parents be productive while still caring for their babies.
Evidence from the Upper Paleolithic age, about 15,000 to
11,000 years ago, suggests the earliest use of baby carriers, likely made from
natural materials such as plant fibres or animal hides.
Some suggesting invention of the carrier happened around 2 million
years ago with Homo erectus. The ability to carry infants effectively allowed
Homo erectus to spread globally, aiding human migration.
Infants carrying in slings may enhance brain development,
shifting from prenatal to postnatal growth, and boosting intelligence. It supports
neocortex development crucial for language and culture. Carrying influences
fine motor skills and manual dexterity, with left-side preference connecting to
the right hemisphere for social processing.
Carrying benefits babies, promoting social and cognitive
growth, and fostering emotional bonds through skin-to-skin contact. This positively
impacts future generations through epigenetics.
Carrying isn't just a trend; it's in our genes. Over fifty-five million years, parents, including humans, carried infants, aiding language
development and social bonds. Recognizing carrying as a biological norm passed
down through evolution underscores its importance in natural infant care.