Maternal Instinct


All living creatures in nature run away from their natural enemies to avoid being swallowed up. However, the courage from the maternal instinct even makes the creatures go against that providence of nature. A giraffe attacks five hungry lions without the slightest sign of fear in its face; and a squirrel risks its life to fight a snake. It is only for one reason—to protect their young. In the sea, a shark that attacked a baby dolphin died as its mommy dolphin butted the shark. The desperate struggle of the mothers to protect their young in the heartless world of wild animals is amazing and touching.

Humans are no exception. A mom personally rescued her immature daughter who had run away to marry a member of a radical militant group. The daughter who went to the militant’s group’s operational base soon regretted what she had done and reached out for help from her mom. In the situation where even the government couldn’t do anything, the mom risked her life to rescue her daughter. Her courage was truly amazing. There are many stories that show the power of maternal instinct like about a baby who survived in a disaster, kept safe in the arms of his mom, and about a mom who saved her child with superhuman power. We can easily find the power of maternal instinct everywhere around us, and everybody empathizes with this.

Motherhood changes a woman’s brain

Many moms say that after having a child they find themselves doing things that they couldn’t even imagine doing before giving birth, as if they have been reborn. What on earth happens to them?

Immediately after childbirth, a woman experiences severe forgetfulness. It is because her brain shrinks as she provides a huge amount of nutrition to the fetus. However, as time goes by, her brain is restored to the original state. At that time, the brain is reconstructed, and its functions improve and it comes to have a better concentration.

Craig Kinsley, a neurologist, conducted an experiment, where he dissected the brains of late-term pregnant mice and discovered that their hippocampal neurons, which play a central role in learning and memory, had been rearranged complicatedly. It means that the mother’s brain is reconstructed to raise the child well. Animal behavior experiments also show that mother mice respond much faster to food than nulliparous mice. It is because the mother mice’s senses of hearing and smell develop and they become agile.

This applies to humans as well. Moms may feel lethargic for the first few weeks after childbirth, but their senses improve and they come to have active responses to things around them. That is why they are always the first ones to notice their babies waking up and to get up, and they quickly recognize the changes of their babies that other people hardly notice. Additionally, they become superwomen who play three or four different roles at the same time, such as cooking, talking on the phone, and taking care of their babies.

Women suffer an inexpressible pain while giving birth to their babies, but amazingly enough, they feel deep peace after delivery. It is due to oxytocin. Oxytocin is a hormone that relieves their anxiety and helps them love their babies. It also suppresses the secretion of stress hormones, improves their social skills, and strengthens their learning ability.

As it was mentioned at the beginning, moms become brave even in fearful and dangerous situations if it is for their children. It is assumed they do so under the influence of hormones. There still has to be more research on it, but it has been proven that two types of hormones are related to the bravery of mothers when it comes to their children. The anti-stress hormone “oxytocin” and the milk-producing hormone “prolactin” get rid of anxiety and fear. “Prolactin works in the brain and makes moms brave,” says Inga Neumann, a German neurobiologist who participated in the research of prolactin. The reason many mother mice get caught in the traps while their milk is produced is they search even dangerous places for their young.

Maternal love’s biological program

The maternal instinct of living creatures is sacrificial and devotional. The mother’s care coming from the maternal instinct helps her young survive in dangerous environments. Asian black bears give birth in winter when they hibernate without eating anything, and survive the long winter, giving milk to their young despite their hunger. The stories about the mother dogs or cats, which raise their young well though they are homeless, let us feel the greatness of motherhood.

Before, people took maternal instinct for granted. However, the research of Terkel and Rosenblatt provided an important opportunity to view the maternal instinct from the scientific point of view. They took a blood sample from a mother mouse within 48 hours of its delivery, and injected it into a nulliparous mouse. Then the nulliparous mouse breastfed the young, although no milk was coming out, and took care of them as if she had given birth to them. This showed the mother mouse’s blood that was taken immediately after delivery has something that induces maternal behavior.

Later it was proven that oxytocin is the very hormone that induces the onset of maternal behavior. The oxytocin hormone helps a woman get through labor and stimulates her body to produce milk. It also creates an emotional bond between the mother and her baby and encourages the mother to protect and raise her baby.

There was also a change in the level of dopamine in the mother mouse’s brain. When the mother mouse made physical contact with her baby, the level of dopamine was suddenly raised. Dopamine is the hormone of joy and happiness. Drugs stimulate or activate the release of dopamine. One research team in the U.S. conducted an experiment to see to which the mother mice would respond, cocaine that is a type of drug or their babies. Generally, cocaine-addicted mice prefer cocaine to food. However, the early-postpartum mice in the experiment spent most of their time taking care of their babies, without paying attention to cocaine. It’s because the mothers feel more joy and happiness when they are with their young than when they snort cocaine.

Cuteness is a common feature of all baby animals; their heads are large in proportion to their body sizes; their eyes are big compared to the size of their heads; they have short arms and legs and round body shapes; and they show awkward body language. Konrad Lorenz, a German ethologist, called the cute characteristics of baby animals, which arouses a protective instinct in adults, “baby schema.” This motivates caretaking behavior in mothers and other adults.

Moreover, when mothers see the instinctive behaviors of their babies, they cannot help but love them. About a month after the birth, babies babble and smile at someone looking at them. According to the findings of a research, a child’s smile helps produce dopamine in the mom’s brain and makes the mom feel happy. When this happens, the mom feels more love for baby. There are some reflexes that all newborn babies have, such as grasp reflex which is to grasp whatever touches their palms, embrace reflex which is to try to hold on to someone when surprised, rooting reflex which is to turn the face to the stimulus, and suck reflex which is to suck anything that is placed to their lips. These instinctive behaviors of the babies create emotional bonds between them and their mothers. Actually, their instinctive behaviors do not come from their special affection toward their mothers. However, the mom who gave birth to a baby feels maternal instinct for the baby, and spends much time with the baby. So, the baby naturally shows the instinctive reactions to the mom, and the mom’s love for her baby deepens. From six months after birth, the baby starts to feel affection toward the mom. The mom and the child have such an inevitable bond, being predestined to love each other.

“Women are weak, but mothers are strong.”

Women may be weaker than men. However, they become stronger than anyone else for their children once they start being called by another name, “mother.” This maternal instinct is the source of strength that helps preserve and sustain human life. The maternal instinct has been handed down from the mother’s mother, and from her mother. Where did it originate?

Marc Bekoff, The Emotional Lives of Animals: A Leading Scientist Explores Animal Joy, Sorrow, and Empathy — and Why They Matter, New World Library, 2008
Vitus B. Dröscher, Wildly Successful: Survival Strategies in the Animal Kingdom (in German, Tierisch erfolgreich: Überlebensstrategien im Tierreich), Goldmann, 1996
Katherine Ellison, The Mommy Brain: How Motherhood Makes Us Smarter, Basic Books, 2006
Kang Seok-gi, Your Brain Becomes Smarter When You Become a Mom (in Korean, 엄마가 되면 뇌는 더 똑똑해진다), Science Donga, September, 2012
Kim Hyeong-geun, Women Are Weak, But Mothers Are Strong (in Korean, 여자는 약하다, 그러나 어머니는 강하다),