For Families > Keeping Kids Healthy > Growth and Development

How important are the first three years of a baby's life?

by Anita Gurian, PhD and Robin F. Goodman, Ph.D.

An interview with David Steinberg, M.D.

The impact of the first three years of life is an issue that will be debated well into the new millennium. Expert opinions, based on findings from the new brain science as well as a century of parental observations and clinical research, provide some clues about the optimum environment to stimulate the brain and development of the 0-to-3 year old.

An explosion of books, articles and media attention on the development of the baby brain is taking place. One question currently being debated is: how crucial are the experiences of the first three years to a child's future behavior, intelligence, and emotional health? Some developmental specialists believe that if 'critical periods' in brain development are not utilized, opportunities are lost, never to be regained. Others maintain that since brain growth continues after the age of three, opportunities for growth do not shut down. It is their belief that emphasis on providing early intervention services has resulted in neglect of attention to older children. It seems that all too often facts and fiction merge, and the details of research have been exaggerated and applied in unfortunate ways. In order to find out what is actually known at the present time about brains and early development and parenting, we interviewed David Steinberg, M. D.

AboutOurKids: We see babies growing at a rapid pace physically; are their brains growing at the same rate? What's going on inside the head that we don't see?

Dr. Steinberg: By the time a baby is born she will have l00 billion brain cells, but these cells aren't yet connected in circuits the way they will be as the brain matures. In the first three years of life the brain rapidly forms connections between brain cells, and ultimately a single cell can connect with as many as 15,000 other cells.

How do these circuits or connections work?

Think of a telephone system with a lot of dialing going on. The circuitry of connections is made up of cells called neurons, which are connected to each other by dendrites. Dendrites are really 'cell phones' which enable neurons to talk to each other. However, dendrites don't actually touch each other. Between the dendrites are spaces called synapses. Information is carried from one cell to another across the synapses by means of chemicals called neurotransmitters. So, the communication highway in the brain goes like this: a neuron sends a signal through its cell phone (or dendrite) that goes to the synapses; a neurotransmitter then takes the message across the synapse and sends it on to the next cell phone (or dendrite) and on to the other neuron.

How do we measure brainpower or capacity in babies? How do we know how many connections the baby's brain is making?

Nerve cells in action burn up fuel, just like muscles. If we measure the amount of glucose, which is the brain's fuel, we can measure brain activity. By three months babies' brains are burning up an increasing amount of glucose. Between age 4 and 9 a child's brain actually becomes twice as active as an adult brain. This activity remains at twice the level of an adult until the child reaches the age of nine or ten.

What happens to the l00 billion brain cells the baby had at birth? Is it important for babies to be making a lot of brain connections?

By the time a child is three the brain has formed about l000 trillion connections, more than it will ever need. Many more communication tracks are laid down than can be used. So a weeding-out process occurs. Careful pruning is done, similar to the way that plants are pruned. By pinching back some things, others are allowed and even encouraged to grow in even richer proportions. The parts of the brain that are stimulated and used will develop and those that are not used will be lost. It's the baby's early experiences that determine which connections are kept and which don't survive. It is theorized that when a connection is used it becomes permanent, but when it is not used it is unlikely to survive.

So if babies have a lot of stimulation at certain times will they stabilize more connections? And what about the child who doesn't get enough stimulation?

The absence of experiences that will stimulate the brain during critical periods can have a lasting impact. Critical periods are times when the brain is most ripe for the learning and acquisition of new skills. Let's consider vision as an example. We know that if a child does not focus one eye appropriately during the critical period of visual development (by 6 years of age) the child will never achieve normal vision in that eye. This happens because the brain was not stimulated during the critical period of visual development. In contrast, if an adult eye is deprived of similar input after the critical period of ocular development, by being patched for a period of time, for example, there will be no lasting deficit.

Are there important periods for development of other abilities?

Are there important periods for development of other abilities? Even though other abilities are not dictated strictly by the critical period phenomenon, an area like language development does have peaks and plateaus. Between the ages of 8 months and 3 years a child's language comprehension and strategies become more sophisticated. For example, an 8-month-old understands a few single words and will look at an object when directed verbally, whereas a 3-year-old understands a 3-word sentence. With respect to expressive vocabulary, in spite of individual variation, a 3-year-old has a vocabulary of approximately 900 words, a threefold increase from the amount at age 2.

Should children be taught a second language at a young age? Does learning a second language interfere with their ability to master their first language?

Children are best able to learn a new language when they're young. There's no sound data to support the belief that speaking two languages at home will impair a child's language skills.

Are there critical periods for emotional development?

The research on early attachment by John Bowlby and Rene Spitz on "failure to thrive" focused on the development of depressive symptoms in infants deprived of emotional contact and nurturance. This area of research is not specific, since we do not have a clear understanding of whether emotional deprivation actually causes changes in the brain or changes in behavior. Keep in mind that they were dealing with extreme deprivation and physical or psychological neglect.

Do we know if neglect or other bad experiences actually harm the brain or cause emotional problems?

Not every child who experiences neglect or bad experiences reacts in the same way. Genes matter, and experience matters. There is an interplay between biological vulnerability and environmental experiences, and the combination of physiological make-up at birth and subsequent life experiences will result in certain behaviors.

So if a child doesn't get stimulation early in life during a critical period, when is it too late? Is it all over by three?

We don't view brain growth as stopping after age three; brains are plastic and we continue to learn throughout life. But this early age period provides us with a unique opportunity to enhance growth. Intervention is always valuable, but the responses to intervention that occur in the early years are relatively more robust than those that occur later.

It is possible to overstimulate a child? Can there be too much of a good thing?

Overstimulation can be as uncomfortable or unproductive as understimulation. There are many factors that determine how much input a child can utilize. Ability is partially determined by such factors as brain capacity and physical capability. For example, to quote an article in Newsweek, l997, p. 15, "no world champion skater or golfer took up the sport after 12...and at 31 basketball megastar Michael Jordan couldn't retool his visual-motor synapses enough to whack a curve ball." A three-year-old will never roller blade as well as a teenager simply because he doesn't have the physical coordination, muscle strength or even understanding of right and left to be able to do the job. So you would never dream of having him practice roller blading for an hour a day in an effort to create a roller blading star. Although there is a wide range of abilities for any given age, the optimum that any one child can do is usually fixed. There is no data to demonstrate that babies whose parents read to them or who are exposed to recordings of classical music in utero or in infancy will outperform babies who do not get this stimulation. However, it is always beneficial for parents to feel close to their baby.

How do you account for the fact that two kids the same age will have different abilities and different styles?

First, consider temperament. Children are born with particular tendencies in regard to internal regulation and preferences in regard to sensory stimulation. Some babies and toddlers crave stimulation and others are hypersensitive and actually avoid stimulation. Parents of more than one child understand this as soon as their second child is born. There is an optimum amount of stimulation that fits within e ac h individual's comfort zone. It's the parents' job to provide the right balance. Like parenting, stimulation works best when there is a "goodness of fit" between the child receiving the stimulation and the amount and source of the stimulation. Parents should be tuned in to what their child is capable of doing and then they should hold out the developmental carrot and gently prod their child to the next level.

What can parents and educators do in the first three years to influence skill acquisition?

You're making a leap between good enough and optimum. There's a difference between pathological deprivation and neglect of necessary environmental stimuli and not investing in every advertised extra educational product or opportunity. We don't have evidence to support the idea that more than good enough is going to make your baby even better. Playing classical music can't hurt, but we know nothing about its effect on the development of musical ability. There are lots of books and magazine articles on this question, but no data. I'm a firm believer in letting a child be a child and encouraging parents to respond to cues from their child about what's enjoyable.

What does the research show about the value of intervention at an early age?

One example is the Abecedarian Project, a long-term study that has been tracking children of African-American families in North Carolina since l972. According to the New York Times, October 24, l999, the study "found strong evidence that high-quality day care indeed enhanced not only the ABCs and mathematical skills but one's success in adulthood." These results are encouraging, but there are still a great m any questions to be answered. Without a doubt, prevention of disorders and problems is better than treating problems once they've been established.

Should society's resources be focused specifically on young children?

The field of early intervention is relatively new but filled with great optimism, founded on the perspective that the earlier struggles are dealt with, the better and more positive will be a child's ultimate development. Certainly children of all ages who need intervention should get it.

AboutOurKids Commentary

What can parents learn from the new findings on early brain development? It seems the most reasonable approach to providing a stimulating and nurturing environment is to avoid extreme positions. To think that a baby's brain is hot-wired at birth and needs a heavy dose of stimulation during the first three years is to reduce parents to data managers and information providers. Don't forget about real relationships, which have been proven to have significant and long-lasting impact on a child's development.

About the Author

David Steinberg, M. D., is Director, Infancy and Early Childhood Program, NYU Child Study Center, and Assistant Professor of Clinical Psychiatry, NYU School of Medicine.

References and Related Books

Bruer, J.T. (1999) The Myth of the First Three Years: A New Understanding of Early Brain Development and Lifelong Learning. Free Press

Campbell, F. A. & Ramey, C. T. (1995) Cognitive and school outcomes for high-risk African-American students at middle adolescence: Positive effects of early intervention. American Educational Research Journal, 32(4)742-772.

Dawson, G & Fishcer, K. (1994) Human Behavior and the Developing Brain. NY: Guilford.

Gopnik, A., Meltzoff, A. & Kuhl, P. (1999) The Scientist in the Crib: Minds, Brains, and How Children Learn. William Morrow

Newsweek (Spring, Summer, l997) Special Edition: Your Child.

Spitz, R. A. (1945). Hospitalism: An inquiry into the genesis of psychiatric conditions in early childhood. Psychoanalytic Study of the Child I:53-74.