Optimizing Expression of the Common Human Genome for Child Development

Molecular biology has moved the gene-environment issue in behavior genetics to how and when expression of the human genome is trig gered and maintained. How does environment influence gene expression? How many genes are expressed in produc ing a given behavior? The genome is a data bank and does not automatically create a working brain. The body and brain grow well when (a) en docrine hormones initiate and promote the expression of genes, (b) nutrition is sufficient to sustain the production of proteins, and (c) stress does not suppress gene expression. The growth of brain synapses also requires appropriate neu ral stimulation. To study gene expression, it is essential to view the complex biology of the cell from a system context that includes the entire genome plus the biological and psychological environments. Optimizing gene expression for child growth can be achieved by a balance of medi cine, nutrition, and appropri ate physical, educational, and psychological environments.