Children do not grow and develop by any haphazard process. Too often parents have had so little, either of first-hand acquaintance with other children, recollection of their own childhood, or knowledge of the literature of child-study, that they have fumbled in the dark, misunderstanding and experimenting on their own children, without either standards for comparison or principles for guidance.

There is a wealth of material, both technical and popular, available in this “century of the child.” The impetus given to the study of the child by Pestalozzi and Froebel a century ago has gained increasing momentum in Europe and America. Some investigators have made laborious studies of large numbers of children to ascertain average rates and factors of growth or development of some part of the body or some phase of spirit. Others have made painstaking, intensive studies of individual children and have reported the characteristics observed at different ages.

The outlines, main features, and basal principles are already defined. A knowledge of these is as essential to the intelligent worker with children as a knowledge of the processes of plant growth and development to the intelligent agriculturist. Many blanks and gaps in our knowledge of child development are yet to be filled. The father, mother, teacher who is sympathetic with child nature, who has the scientific mind for accuracy, definiteness and persistence of observation, has an opportunity to contribute to the common fund of knowledge of child life by making original observations of the child in the home. Hitherto most of the published studies, both of groups and of individuals, have been made by men. Doctor G. Stanley Hall has been the pioneer leader and chief inspirer of the child-study movement in America. Doctor John Dewey’s contributions and inspirations have been both profound and extensive. Madame Montessori is the one woman who has made large contributions.

It should be noted that a science of child-study and development was not possible until the idea of evolution became known and appreciated. Froebel sensed this evolution, as will be noted in reading his “Education of Man”, which was published a quarter of a century before Darwin’s “Origin of Species.”

This phase of psychology—tracing the stages of mental development as an organic process from its simple beginnings in the individual or the race to its maturity in adulthood of the individual or civilization of the race—is the field of genetic psychology.

The intelligent worker with children in the home must be acquainted with what is normal and usual at any stage, in child anatomy, physiology, and psychology. Only with such knowledge is it possible to make intelligent observations of the development of the individual child, and to supply a normal environment and guidance suited to his stage of development. Such knowledge and preparation can be acquired only through study of the literature of child psychology, and through intensive, first-hand acquaintance with children.

It requires about twenty-five years for nature to bring a human individual from birth to physiological maturity. In the nine months before birth the growth and development is very rapid. All the organs are formed, but their development at birth is immature, especially the development of the nervous system. What is accomplished in these years?

From Birth to Maturity

Total weightincreases from16 to 22 fold.
Length of body”3fold
Size of muscles”37”
Size of lungs”18”
Size of heart”13”
Size of brain”3”
Weight of arm”4”
Weight of leg”5”

Note the great differences in increase of different parts of the body.