Mother-Baby Bond: The Biology of Love Chapter 12

A Mutual Gaze

Babies’ sensory systems require interaction with the environment in order to mature, which they do quite rapidly. “By 3 months,” says Claire Kopp, “they see nearby objects quite clearly, and in another few months, as well as most adults. Hearing also matures during the first 6 months and, at about a year, is comparable to adult hearing.” At the same time that visual and auditory acuity is improving, explains Kopp, it is also becoming more discriminating. Even when the sensory hardware is all in place, there are elements in vision and hearing that babies gradually acquire through experience, like being able to locate a sound as either distant or nearby or building a knowledge base about faces and objects.

Vision: What Does My Baby See?

While newborns can see objects 2-3 feet away, they see things best when they are only a foot or less away. There are several factors that contribute to these limitations, explains Kopp, involving the shape of the eye and its ability to focus, as well as the immaturity of the “neuronal connections within the brain itself and connections from the eyes to the brain’s vision centers.”

At 4 months, however, the baby “is aware of different primary colors, differentiates shapes, distinguishes sizes, and detects movement, and now begins to recognize differences in texture.” Interestingly enough, notes Kopp, studies show that even with improving visual abilities, 4-month-olds will often “focus on parts of an object rather than on the whole. Babies might be mesmerized by the head and hair of a rag doll and totally ignore its body or feet.”

It is clear, says Kopp, that vision is important to infants. “Babies of 7 months are so intrigued by what they see that they sometimes stop playing to stare at a face.” And within another few months, babies “seem to realize if they make eye contact with another they can then direct the other’s gaze to something else that interests them.” It’s a huge step, explains Kopp, because it shows that they are beginning to know what they need to know and how to go about learning it. The growing ability of a baby to also follow someone else’s gaze plays a role in the baby’s emotional development, because the emotions that other people display are often linked to what they are looking at.


It’s no surprise that babies love faces. Faces are like windows, and through them come the love and attention directed at the baby. As babies make their way in the world, it will also be faces that will be the most visible signal of other people’s emotional states and intentions. It is also probably no surprise, then, that at a certain age, babies become uncomfortable when confronted by blank, expressionless faces, a response that adults can identify with as well. Researchers have discovered a great many other interesting details about babies’ infatuation with faces. A baby’s early experience with faces, according to researchers Jennifer Rennels and Rachel Simmons, “has important implications for social development and, in particular, the development of concepts about different types of people based on appearance,” such as the “ability to discriminate faces within a particular category.”

What this means is that the majority of babies initially become most familiar with female faces. And not only does mom’s gender serve as the model for the baby’s first category of faces, her age and race also become early templates. Laboratory studies have shown that in the first 6 months, babies will prefer female to male faces and same-race to other-race faces. Babies even seem biased to prefer faces of a similar age to mom. It’s a finding that can give us pause. As Rennels and Simmons observe, “Such perceptually based social categories may form the basis from which appearance-based stereotypes develop.” Thankfully, outside the lab in the real world, frequent experience with non-mom faces will broaden the baby’s experience.

The flipside of recognizing faces, of course, is making faces, and babies become masters of that as well. Anthropologists have identified six basic expression categories that seem to hold across cultures, although the details of what is or isn’t culture-specific continue to be a source of argument. What no one disputes, however, is that faces and facial expressions attract attention, and babies become experts at using their own facial expressions to draw and keep the attention of mom and others. “Even babies born blind, who have never seen anyone make faces, start to smile around 6 weeks of age in response to touch, bouncing, or the sounds of a familiar voice,” writes Sarah Blaffer Hrdy in Mother Nature.


Babies can hear well before they are born. “Sounds, or at least vibrations, pass through the mother’s abdominal wall and bathe the fetus in communications from the world outside the womb,” explains Claire Kopp in Baby Steps. “Toward the end of the prenatal period, around the middle of the seventh month, fetuses actually begin to hear speech intonations...and to differentiate what they hear. Because the fetus hears the speech of one person—the biological mother—more than any other, studies have shown that babies in the first few weeks of life outside the womb not only differentiate their mother’s speech but actually prefer it.”

In the first few months, a baby’s range of hearing widens in several ways. Initially, explains Kopp, babies can hear someone “who speaks in a normal everyday voice,” but “they do not detect whispers.” Soon this changes and the baby can detect even “tiptoe steps and the rustle of paper being crumpled.” Babies are initially most responsive to high-pitched voices, again an adaptation designed with mom in mind. Babies also come to detect expressions of affect, or emotions, in voices. Recognizing these subtleties is crucial because voices carry such a wealth of emotional content. Parents shouldn’t worry about the exact timing of these milestones, says Kopp; they should talk, sing, and read to their infants as early and often as they can!


Hand-in-glove with developing auditory abilities are the skills that will form the foundations of language. It is easy to think of language as the pinnacle of development—and of course in many respects it is. As Steven Pinker has stated, “language imposes greater demands on the brain than any other problem the mind has to solve.” But it still has much in common with other aspects of development: it requires both innate human potential and stimulation from the real world to come to fruition. Language does not develop in isolation from the rest of growth and development.

By 1 or 2 months, infants can make some distinctions between the sounds of certain vowels and consonants as well as differences in tone. Babies can also distinguish speech sounds from non-speech sounds. And that’s just the beginning of the learning curve. Babies clearly have the capacity to learn any language in the world. Not so for their older siblings, at least not as perfectly; as early as 6 months can mark the point at which a baby begins to lose some tiny nuance in the ability to discriminate subtle sounds in certain languages.

In recent years, a promising area of research has been the study of babbling. It might seem obvious that babbling would lead to language, but the connection is probably much more complicated. Anthropologists have looked closely at babbling, as well as the coochy-cooing known as motherese, and have speculated on the evolutionary origins of these vocalizations and the ways in which these behaviors might have helped both mothers and infants maintain their bond. We are not likely to ever get a definitive answer, but as Hrdy observes, “The power of babble, I suspect, preceded the gift of gab by more than a million years.

Link Between Maternal and Romantic Love

The language is a bit dry, but the summary of the academic research paper The Neural Correlates of Maternal and Romantic Love hits the nail on the head: “Maternal and romantic love are highly rewarding experiences. Both are linked to the perpetuation of the species and therefore have a closely linked biological function of crucial evolutionary importance.”

In the paper itself, researchers Andreas Bartels and Semir Zeki are far more poetic: “The tender intimacy and selflessness of a mother’s love for her infant occupies a unique and exalted position in human conduct. Like romantic love, to which it is closely linked, it provides one of the most powerful motivations for human action, and has been celebrated throughout the ages—in literature, art and music—as one of the most beautiful and inspiring manifestations of human behavior.”

And yet, as Bartels and Zeki point out, too little is know about the neural pathways that underlie maternal love. What researchers are discovering, however, is that the two expressions of love do indeed share much in common. Studies of various mammals, from rodents to primates, show that the same neurohormones (oxytocin and vasopressin) are involved in the bond between mother and child and in the long-term pair bonding between adults, although there are some differences in which gender and where in the brain each neurohormone is most active.

Researchers are using sophisticated tools such as functional magnetic resonance imaging (fMRI) to map the neural architecture of maternal and romantic love and are finding that the two are different in some respects and identical in others. Interestingly, maternal and romantic love don’t just activate areas in the brain; they also deactivate certain other areas, regions associated with negative emotions and social judgment we use to scrutinize other people’s intentions and emotions. People in love with babies or each other, it appears, suspend the sort of judgments that might interfere with their positive feelings.

Or, in the language of science: “We conclude that human attachment employs a push-pull mechanism that overcomes social distance by deactivating networks used for critical social assessment and negative emotions, while it bonds individuals through the involvement of the reward circuitry, explaining the power of love to motivate and exhilarate.” Indeed.

More on this topic

Mother-Baby Bond: The Biology of Love (VIDEO)

Mother-Baby Bond: The Biology of Love

Establishing New Life

Nurture & Protect

Growth & Sensations

Adapting & Anticipating

Joyous Mom, Joyous Baby

Your Baby Enters the World

Nourishing Body & Bond

Mother & Teacher

Nurturing Development

A Mutual Gaze

From Bump to Bundle

Related Health Centers:

Infant Nutrition Health Center, Mother-Baby Bond Health Center, Mother’s Milk Health Center, Monthly Infant Development Calendar Health Center,Weekly Pregnancy Calendar Health Center

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