What is ontogeny and phylogeny?

G. Stanley Hall, answered from the texts and cited to the page.

G. Stanley Hall answers

The two terms name the twin axes on which all my psychology turns. Ontogeny is the development of the individual organism from the moment of conception — that instant when the male cell penetrates the ovum and the long anagenic series begins — through every stage of growth until full maturity is reached.¹ Phylogeny is the developmental history of the race, the vast ascent of organic life through its successive types, from the protozoan upward through invertebrate, fish, amphibian, reptile, and anthropoid to man.²

The great principle that binds them is this: the individual, in growing, repeats the history of the race. Ontogeny recapitulates phylogeny. The child passes biologically through a series of types that mirrors the whole evolutionary ascent — fishlike gill pouches at three weeks, amphibian traces at five, reptilian characters through the third month, the anthropoidal form gradually emerging thereafter.³

But the recapitulation does not stop at birth, and it is not merely anatomical. Psychologically the growing child re-lives the mental epochs of our ancestors just as surely as the embryo re-lives their bodily forms. The infant's atavistic postures, the child's ready-made fears, the nomadic impulse that sends boys running away from home, the hunting passion, the collecting instinct — none of these are learned from individual experience; they surface on their appointed schedule because they are the deposits of an immense ancestral past.⁴

Holding that the child and the race are each keys to the other, I have constantly sought phyletic explanations of the stages of growth, convinced that only here can we find true norms against the tendencies to precocity that home, school, church, and civilization press upon the young.⁵ Play itself, in this light, is the rehearsal in the midst of our own life of very ancient paleopsychic activities that belong to an earlier epoch of the race — and the practical field for the recapitulation theory is nowhere richer than in the years just before and into the teens.⁶

To know what stage of racial history a child is living through is to know how to educate him; to ignore it is to thwart nature at her most formative moment.

Sources

1. The beginning of individual life, or the age of zero for all sexed animals, is when the male cell penetrates the ovum... the long series of anagenic processes that end in complete maturity.

   Adolescence Vol 1

2. Biologically the child passes through a series of types ranging from protozoan to man.

   Aspects of Child Life and Education

3. At conception the organism is a minute unicellular structure, by the second week it suggests an invertebrate type, at three weeks it has fishlike gill pouches, by the fifth week it has developed amphibian traces... thence on to the middle of the third month reptilian characters are found.

   Aspects of Child Life and Education

4. Psychologically there are many things explained only by the recapitulation theory. In dreams, the old racial fears often make nights miserable... The tendency of children to run away is an echo of the migratory impulse of our ancestors.

   Aspects of Child Life and Education

5. Holding that the child and the race are each keys to the other, I have constantly suggested phyletic explanations of all degrees of probability... only here can we hope to find true norms against the tendencies to precocity in home, school, church, and civilization generally.

   Adolescence Vol 1

6. Play in general is the rehearsal in the midst of our own life of very ancient paleopsychic activities which belong earlier in the race. Thus, on the whole, I believe the very best possible practical field for the recapitulation theory is just at this stage.

   Educational Problems Vol 1