| Physical Characteristics | Youth Girls, 9-12 years Boys, 9-13 years |
Early Adolescence Girls 12-16 years Boys 13-18 years |
| Height | Slow growth; girls more rapid than boys | Rapid increase (Girls, 11-14) (Boys, 13-17) |
| Weight | Slow growth | Rapid increase ” ” |
| Organs rapidly growing | Legs, arms | Trunk, legs, arms, lungs, reproductive organs, heart, liver, kidneys; proportions changing |
| Organs proportionately large | Arteries | Hands, feet, arms, legs |
| Organs proportionately small | Heart, trunk arteries | Trunk, internal organs, |
| Organs proportionately strong in function | Muscles, legs, eyes | Heart, lungs; blood pressure high; muscles, fundamental and accessory |
| Organs proportionately weak in function | Heart, lungs; blood pressure; elimination | Nerves; internal organs, elimination; motor coördinations because of change in bodily proportions |
| Dentition | Complete (except wisdom teeth) | |
| Nerves | Reactions vigorous | Under strain; easily unbalanced |
| Sense development | Complete, including eyes | Senses keen |
| Special organs or systems at developmental stage, needing much immediate exercise | Muscles of trunk, forearm, fingers; motor adjustments; lungs | Muscles of trunk, arms, legs, fingers; lungs |
| Defects easily acquired | Spinal curvature, eyestrain; precocious sex development | Of reproductive system; shallow breathing |
| Defects easily overcome | Bones, teeth | Bones, lung capacity |
| Illness most susceptible | Anemia, rheumatism, heart weakness, nervousness; period of low morbidity | Anemia, nervousness, malnutrition; tuberculosis (girls); increased morbidity |
| Most common immediate causes of death | Period of low mortality. Pneumonia, tuberculosis, diphtheria and croup, heart and kidney diseases, accidental drownings | Pneumonia, tuberculosis, kidney and heart disease, accidental drownings |
| Nature and rate of mentality | Direct, alert; more orderly, controlled | Well coördinated, more abstract, logical, comprehensive; routine irksome |
| Motor activities | Well coördinated; need much exercise; new adjustments readily made | Muscular awkwardness during growth |
| Sense activity | Sure, acute, subordinate to thought | Acute; all senses |
| Attention | Voluntary increasing | Potential voluntary attention strong |
| Perception | Clearer | Clear |
| Curiosity | Less keen | Wide range; persistent; craving for larger experience |
| Imitation | Less marked; of idea rather than action | Of ideals, strong; originality marked; individuality |
| Memory | Quick, sure, lasting; period of rote learning | At best; logical |
| Imagination | Clear, creative | Vivid, comprehensive, creative; works for remote ends |
| Construction | Constructs for purpose; interest in workmanship, skill | Interest in technique, use, æsthetic qualities |
| Reasoning | Immature; by analogy or suggestion; logic premature | Logical, abstract; mental speculation |
| Social instincts | Less sympathy with adults, more with companions; competition increases | Strong sympathies; group loyalty; altruism; sex instincts developing |
| Sense of law | Increasing through games; contempt for artificial laws, customs; less submissive to authority | Conscience keen; marked lawlessness or law abiding; restive of restraint |
| Emotions | Weaker; fears increase; sex consciousness developing | Keen, subjective, whimsical; shyness and bashfulness; romantic love develops |
| Sense of humor | Keen, expressed in teasing, practical jokes, puns | Strong; riddles, puns |
| Will | Self-will increasing; tendency to vacillation, inertia | Self-will strong; potential will power |
| Religion | Conscience weak; reverence weak; religious indifference; formal interest in religious ceremonies, forms | Deep religious feeling or irreverence Idealism; mysticism; altruism. Conversion period |
The tables of physical characteristics are based upon the work of Vierordt, Uffelmann, Schmid-Monnard, Pfaundler and Schlossmann. Holt, Kerley; the tables of mental characteristics upon the studies of G. Stanley Hall, John Dewey, Earl Barnes, and their disciples, and the summaries of Kirkpatrick, Tanner, Taylor, Tracy. The author’s personal experience with children, as a medium for developing these data into a composite grouping, has been supplemented by the criticisms and suggestions of individual physicians, biologists, and psychologists. The subject deserves much additional research in the comparative study of children.
FOOTNOTES:
[2] Based on U. S. Census Report for 1913; causes arranged in decreasing rank.