Education and the Brain: A Bridge Too Far j OHN T. BRUE R Educational Researcher, Vol . 26, No . 8, pp. 4-16 place, that indirectly link brain function with educational practice. There is a well-established bridge, now nearly 50 years old, between education and cognitive psychology. rain science fascinates teachers and educators, just as There is a second bridge, only around 10 years old, between it fascinates all of us. When I speak to teachers about cognitive psychology and neuroscience. This newer bridge Bapplications of cognitive science in the classroom, is allowing us to see how mental functions map onto brain there is always a question or two about the right brain ver­ structures. When neuroscience does begin to provide use­ sus the left brain and the educational promise of brain­ ful insights for educators about instruction and educational based curricula. I answer that these ideas have been practice, those insights will be the result of extensive traffic around for a decade, are often based on misconceptions and over this second bridge. Cognitive psychology provides the overgeneralizations of what we know about the brain, and only firm ground we have to anchor these bridges. It is the have little to offer to educators (Chipman, 1986). Educa­ only way to go if we eventually want to move between ed­ tional applications of brain science may come eventually, ucation and the brain. but as of now neuroscience has little to offer teachers in terms of informing classroom practice. There is, however, a The Neuroscience and Education Argument science of mind, cognitive science, that can serve as a basic The neuroscience and education argument relies on and science for the development of an applied science of learn­ embellishes three important and reasonably well-estab­ ing and instruction. Practical, well-founded examples of lished findings in developmental neurobiology. First, start­ putting cognitive science into practice already exist in nu­ ing in infancy and continuing into later childhood, there is merous schools and classrooms. Teachers would be better a dramatic increase in the number of synapses that connect off looking at these examples than at speculative applica­ neurons in the brain. This synaptic proliferation (synapto­ tions of neuroscience. genesis) is followed by a period of synaptic elimination. The teachers' questions arise out of the perennial interest Second, there are experience-dependent critical periods in in the brain and neuroscience that has always existed at the the development of sensory and motor systems. Third, in margin of educational research and reform discussions. Re­ rats at least, complex, or enriched, environments cause new cently, however, interest in how neuroscience might im­ synapses to form. prove education has moved from the margins to center The argument runs as follows. Starting in early infancy, stage. Educators and education policy experts are the most there is a rapid increase in the number of synapses or neural vocal enthusiasts. Educational writers, likewise fascinated connections in children's brains. Up to age 10, children's by the brain but puzzled by the mind, have picked up on brains contain more synapses than at any other time in their this enthusiasm. Over the past year, there have been nu­ lives. Early childhood experiences fine-tune the brain's merous books, journal articles, policy studies, and stories in synaptic connections. In a process that we might describe as the media about how our emerging understanding of brain synaptic pruning, childhood experiences reinforce and development and neural function could revolutionize edu­ maintain synapses that are repeatedly used, but ~nip away cational practice. 1 Neuroscientists, while interested in how the unused synapses. Thus, this time of high synaptic den­ their research might find application outside the laboratory sity and experiential fine-tuning is a critical period in a and clinic, are more guarded in their claims. Often they are child's cognitive development. It is the time when the brain puzzled by the neuroscientific results educators choose to is particularly efficient in acquiring and learning a range of cite, by the interpretations educators give those results, and skills. During this critical period, children can benefit most by the conclusions educators draw from them. from rich, stimulating learning environments. If, during This article examines those results, interpretations, and this critical period, we deprive children of such environ­ conclusions-a set of claims that I will call the neuroscience ments, significant learning opportunities are lost forever. As and education argument. The negative conclusion is that one popular article put it, "with the right input at the right the argument fails. The argument fails because its advocates are trying to build a bridge too far. Currently, we do not know enough about brain development and neural func­ tion to link that understanding directly, in any meaningful, JoHN T. BRUER is president of the James S. McDonnell Founda­ defensible way to instruction and educational practice. We tion, 1034 S. Brentwood Blvd., Suite 1850, St. Louis, MO 63117; may never know enough to be able to do that. The positive phone 314-721-2068; e-mail [email protected]. He specializes in conclusion is that there are two shorter bridges, already in cognitive science and the philosophy of science. 4 EDUCATIONAL RESEARCHER time almost anything is possible," but "if you miss the win­ tion points for helping children develop knowledge and dow you're playing with a handicap" (Begley, 1996, p. 56). skills, positive attitudes toward learning, healthy behav­ Educators appeal to this argument to support a number iors, and emotional attachments of powerful and endur­ of claims. E. D. Hirsch Jr. (Hirsch, 1996) uses it to argue that ing significance. If these opportunities are squandered, it Jerome Bruner was actually correct to claim that any subject becomes progressively more difficult and more expensive can be taught effectively in some intellectually honest form to make up for the deficits later on. (Carnegie Task Force, 1996, p. 10) to any child at any stage of development. According to Hirsch, Bruner's claim now "represents the current think­ What's wrong with this? In its synopsis, Years of Promise ing in mainstream neurobiology. 'Nature' is actually telling cites two neuroscience articles and a keynote address on us something very different from the message carried by brain development given by a science journalist. These are the phrase 'developmentally appropriate.' What nature is the only references to the neuroscience literature in the en­ really saying about much learning much of the time is 'the tire report. Yet, it contains hundreds of citations to the cog­ earlier the better'" (p. 223). For Hirsch, neuroscience nitive, developmental, and social psychology literature. proves that "developmentally appropriate" are dirty This latter literature, not the neuroscience, provides evi­ words. dence for the report's significant claims about the impor­ The claim that children are capable of learning more at a tance of early childhood. And, unfortunately, it has been very early age, when they have excess synapses and peak primarily the neuroscience angle that commentators have brain activity, is one of the more common ones made in the seized on in their secondary discussions of the report. neuroscience and education literature. Neuroscience im­ When I received a telephone inquiry from a journalist about plies that if information is presented in ways that fit each the report, she wanted to know what I would advise par­ child's learning style, children are capable of learning more ents about choosing a preschool based on what neuro­ than currently believed (Education Commission of the science tells us about brain development. My answer was States, 1996, p. vi). On this same evidence, other articles brief: "Based on neuroscience, absolutely nothing." urge that children begin the study of languages, advanced We can't choose preschools based on neuroscience. Nor mathematics, logic, and music as early as possible, possibly can we look to neuroscience as a guide to improved educa­ as early as age three or four. Parents should realize that they tional practice and policy. Our fascination with the brain have a "golden opportunity to mold a child's brain. And leads us to overlook and underestimate what behavioral that calls for a full-court press during the early years-that science can already provide to improve policy and practice. is, a rich child-care environment without undue academic The neuroscience and education argument may be rhetori­ stress" (Viadero, 1996, p. 32). Parents should become deeply cally appealing, but scientifically, it's a bridge too far. To see involved in their children's early education because "when why, let's review what neuroscientists do know about brain activity is high, parents have a unique opportunity to synaptic growth, critical periods, and enriched environ­ foster a love of learning" (Abelson, 1996, p. 1819). One jour­ ments. nalist claims that, ideally, "at age 2'12 or 3, children would start at Montessori school, where the educational program Synaptogenesis comes closer to matching neurological findings than any I At birth, both nonhuman and human primate brains con­ know" (Beck, 1996, p. 23). tain synapses that connect brain cells into circuits. The neuroscientific evidence shows, according to a vari­ Neonates have slightly fewer synaptic connections than do ety of educators, that there is a critical period for learning in adults. However, early in postnatal development, the in­ early childhood that is somehow related to the growth and fant brain begins to form synapses far in excess of adult pruning of synapses. The ages for this critical period vary­ levels. This process of synaptic proliferation, called synap­ birth to 3 years, birth to 6, birth to 10, 3 to 10. Educators cite togenesis, continues over a period of months that varies this evidence to explain why some early childhood pro­ among species.