Right after the turn of the century, Pat Kuhl, who studies speech and hearing at the University of Washington, ran a pair of experiments with English-speaking nine-month-old babies. Parents brought their infants to her lab 12 times for 25-minute sessions, with the group divided into two. One group spent the sessions with a native Mandarin Chinese speaker who sang, played, and spoke with the infants; the other did the same activities in English. After 12 sessions, the researchers measured how well the babies could distinguish Mandarin Chinese sounds. The babies had basically become native listeners: they could recognize as many sounds as infants raised in Taiwan.
Kuhl and her researchers then ran a second set of experiments, this time with the same researcher doing the same songs and activities and chatter, but on a TV. A different group listened to an audio recording. The babies in these experiments learned nothing.
Kuhl’s findings may seem relevant to the debate over the merits of screen time, or the benefits of raising bilingual babies. To scientists, the experiments suggested something far more radical: infants are highly social learners—that is, they learn by being connected to people and feeling safe. One of the breakthrough findings of the research was “recognizing that social interaction was at the core of how human brains develop,” says Kathy Hirsh-Pasek, a professor of psychology at Temple University. “It was the special sauce.”
Despite what modern parents are often told (and sold), babies do not need apps promising to get them to read by two, toys promising to prime the brain for math, or more academic activities earlier in life. Experiments like Kuhl’s show that what infants need instead is much simpler: Beyond the obvious—nourishment, sleep, movement, and play—babies need to be safe; to have attentive, responsive, and consistent care; and to be exposed to a lot of language, including through singing, stories, talking, and a lot of cooing (“motherese“).
All that love builds brains and underpins learning. Cuddles, it seems, eventually contribute to calculus.
The challenge in a hyper-connected, fast-moving, tech-addled world is that infants need precisely the inverse of what many parents do all day, which is multi-task, optimize, and produce. Infants need space and time to explore without any goals or objectives, with caregivers who are willing to follow their seemingly boundless interests—blocks for three minutes; a pan for two, a book, maybe to read, perhaps to chew, before making a beeline toward the fluffy dog. They need caregivers who buffer their stress while they learn to manage things themselves. Tech, at least so far, hasn’t found a “solution” for that.
In the mid 1980s, Betty Hart and Todd Risley, psychologists who lived in Kansas, studied how 42 families spoke to their children. The sample was small, but they tracked the families—some on welfare, some working class, and others in professional homes—for three years. They found that the professionals’ children were exposed to an average of more than 1,500 more spoken words per hour than kids in the welfare homes. That’s 8 million more words a year. By age four, rich kids had amassed a 32 million-word gap advantage over poor kids.
That gap became a key to understanding why poor children start school at such a massive disadvantage compared with rich ones. It started a push to expose low-income kids to more language.
New research shows that the most important factor may not be the sheer accumulation of language, but rather the nature of it. A recent study from researchers at MIT, Harvard, and the University of Pennsylvania found that a type of interaction they labeled “conversational turns”—what others have dubbed “serve and return“—was more predictive of a child’s language development than the sheer number of words spoken to them. Using brain scanners, natural language processing systems, and a raft of standardized tests on four, five, and six year olds, the researchers found that conversational turns strongly correlated with both more brain activation and higher test scores. Their findings applied to children regardless of parental income or education.
“It’s almost magical how parental conversation appears to influence the biological growth of the brain,” says John Gabrieli, a professor and member of MIT’s McGovern Institute for Brain Research and the senior author of the study.
In a “serve and return” interaction, an infant “serves” up an interest in something—where they put their attention, moving to what they point to or say, or shifting to what they play with—and caregivers respond by “returning” it: sharing the child’s focus (“that car is blue!”), encouraging it (“that’s right, it’s a car that drives!”), while naming it (to build language) and repeating it. Continuing with this back-and-forth allows young children to know their interests are validated, curiosity rewarded, and exploration encouraged. Hirsh-Pasek prefers the term “conversational duet” because serve and return sounds like it happens just once, and “you can’t sing it alone.”
Scientists are starting to study language development in babies as young as two months. They do this by looking at their attention systems: what they look at and whether they can “attend” to what a caregiver attends to. Joint attention is critical for language development: you have to attend to something to name it.
That said, a recent study published in Child Development claimed to disprove the Hart and Risley findings. It measured language in kids’ homes but found more variation among all socioeconomic groups, rather than such a stark divide between higher- and lower-income families. The study also claimed that Hart and Risley did not account for words that were in the child’s environment, but not directed at the child. Critics noted that the Child Development study only looked at low- and middle-income families, whereas the Hart and Risley study compared the highest and lowest income groups, and cited ample research that in the early years, language directed at children is better than ambient conversation.
In 1955, a team of mental health workers, pediatricians, public health nurses, and social workers started to follow the development of nearly 700 children from Kauai, Hawaii, from age one to age 40. The study became famous for beginning to unpack the roots of resilience, especially among disadvantaged kids.
It found that the children who thrived despite adversity were those who had the support of a caregiver—often a grandparent or older member of the community. “Children who succeeded against the odds had the opportunity to establish, early on, a close bond with at least one competent, emotionally stable person who was sensitive to their needs,” the study notes. “Much of this nurturing came from substitute caregivers, such as grandparents, older siblings, aunts, and uncles.
The Kauai Longitudinal Study underscored the need for children to have secure attachments to adult caregivers. According to Harvard’s Center for the Developing Child, stable, quality relationships in the early years lay the foundations for a vast array of developmental outcomes, including:
- Sound mental health
- The motivation to learn
- Achievement in school and later in life
- The ability to control aggressive impulses and resolve conflicts in nonviolent ways
- Knowing the difference between right and wrong
- Having the capacity to develop and sustain casual friendships and intimate relationships
- …and ultimately becoming a successful parent oneself
Being a caregiver does not mean shaping a child to be like you. Alison Gopnik, a professor of philosophy and psychology at the University of Berkeley, argues that parents and other caregivers should be more like gardeners, providing fertile space for children to thrive, and less like carpenters, seeking a certain outcome. “Even if we could shape our children to come out a particular way, we would have defeated the point of having children in the first place,” she explains. “The point of having children is to have people to do something new, something unexpected, the things we never would have anticipated.”
Babies come equipped, she argues, to learn what they need; we don’t need to mold that. The Kuhl experiment, she notes, isn’t evidence to support teaching babies another language, but evidence that babies learn from whatever is around them.
“Shaping our children, the carpentry model, is a mug’s game,” she says. “It is not something that we can do effectively, it makes us anxious and miserable, and even if we could do it, it’s not clear that we should.”
One thing the grandparents in the Kauai study probably did was act as social buffers: they helped soak up stress so kids didn’t have to. Megan Gunnar, a child psychologist and head of the Institute of Child Development at the University of Minnesota, has been studying attachment and social buffering for 45 years. She has found that when kids have secure attachments to caregivers, they learn to handle stress better. “When the parent is present and the relationship is secure,” she says, “basically the parent eats the stress: the kid cries, the parent comes, and it doesn’t need to kick in the big biological guns because the parent is the protective system.”
Social buffering doesn’t mean parents stop kids from doing things. Helicoptering, snow-plowing, and other forms of overprotective parenting can make kids risk-averse. It also doesn’t mean that parents should freak out when things go wrong. If a parent panics when their child falls, a natural reaction—from an evolutionary standpoint—is that the child will then avoid that thing in the future, which is not ideal if that thing is playing tag instead of running from a lion.
In one recent experiment, researchers tested the cortisol levels of toddlers between 12 and 22 months old when they went in for well-baby visits (kids typically find shots stressful). They wanted to see how income level and attachment interacted with social buffering. Did kids who were poorer, but more securely attached, experience less stress during these visits? They did: lower-income kids with insecure attachments had significantly higher cortisol levels throughout the visit compared to toddlers living in poverty or near poverty with secure attachments. Since poverty is associated with poor physical and emotional development, and children living in poverty are more likely to have insecure attachments, the study underscored how social buffering can protect children from the adverse effects of being poor.
Gunnar’s research shows that social buffering by caregivers early in life is not an “immature form of adult social buffering, but the foundation out of which our capacity to gain stress-relieving benefits from the presence and availability of friends and family emerges.” In other words, caregivers are not just children’s trial run for how to love and learn: they are ones who set up the field so children can love and learn on that field later.
This should be reassuring. Parents don’t need a PhD in developmental psychology: they need to be able to sit quietly with a child and read, talk, listen, respond, and repeat (a gazillion times). “The amount of variability in what the parents do—the things that someone sets out to do—are just messing around the edges compared to what the children are learning by just observing what is going on around them,” says Gopnik. Make the environment safe, caring, and interesting and kids will learn.
After all, children learn English all on their own, and do their own form of advanced statistics, her research shows. “They are much better designed to know what to do in their environment in which they find themselves than any adult or any related technology,” she says.
Modern parenting can make this seem hard. Most parents today don’t have much experience, having never cared for children or watched others doing so. Jobs demand a lot, economic uncertainty is stressful, and technology is moving faster than it ever has before. Parents are anxious for themselves, but more so for what they need to give to their kids to prepare them for the future.
But no matter how fast the world is changing, and how little we know about what it will look like in 10 years (much less 50), development, it turns out, is based on eons of evolutionary biology. And evolutionary biology doesn’t change that fast.
Technology can make it more difficult to be present, attentive, and engaged (so many Instagramable moments!). In one of Kuhl’s more recent studies, she had parents talk and play with their infants and then abruptly turn away to answer a call on their phones. It was a replication of an experiment performed by developmental psychologist Edward Tronick in 1975. Back then, Tronick observed that when babies lost their parent’s attention, they desperately sought to regain it.
The twist in Kuhl’s study was that babies were attached to a magnetoencephalography neuroimaging machine to map their brain activity (which Kuhl describes as as looking like a “hairdryer from Mars”). When the mother looked at her phone, Kuhl told Haaretz, the fear centers of the baby’s brain lit up.
But as technology, and our understanding of it, improves, there may be ways to use it to bolster meaningful connections. Some recent studies found that toddlers learn new language when a video is interactive (like via FaceTime) and there is reciprocity (the researcher on screen responds to the infant). Other studies show that infants can learn from tech if they are with other kids who are also interacting with it (social learning, but from peers).
Science is clear, though, that technology isn’t needed for good parenting. Instead, parents who have their basic needs met (shelter, food, care) already come equipped with what babies need to thrive. More than needing more tech, parents need more human help, the kind aunts and grandparents used to offer. In other words, it takes a village, not an app.