philobiblius

"A very ingenious statement of the case is made by Dr. Bird T. Baldwin. Children, says Dr. Baldwin, have five ages, -

1. A chronological age,
2. A physical age,
3. A mental age,
4. A moral age,
5. A school age.

Two children, born on the same day, have the same age in years. One is bound to grow faster than the other in some physical respect. Therefore the two children have different physical ages, or rates of development. In the same way they have differing mental and moral ages. The school age, a resultant of the first three, is a record of progress in school. Even when children are born on the same day, the chances they will grow physically, mentally, and morally at exactly the same rate, and will make exactly the same progress in school, are remote indeed. School children are, therefore, inevitably different."

The New Education: A Review Of Progressive Educational Movements Of The Day
Scott Nearing, 1915