Not done Sir, but doing.

Plenty is doing.

"{There are three important laws of human development: it is determined by innate rather than environmental factors; the most necessary biological functions develop earliest; and mental and physical development show periodic and alternating fluctuations-mental development occurring markedly between 18 months and 4 years, between 7 and 11 years, and between 14 and 18 years.}"

Mary COLLINS & J.DREVER, 1936, Psychology and Practical Life. London University Press.

Disclaimer: this quote appears here only to spark discussion. It is not endorsed one way or the other. Make up your own mind. Or just refresh the page for another viewpoint. From a collection assembled by the late Chris Brand.