"a little boy of about seven and a little girl who might have been a year older, were playing, very gravely and with all the focused attention of scientists intent on a labour of discovery. A rudimentary sexual game."

divorce rate
Public Domaindivorce rate - Credit: statistics.gov
As disturbing as this may seem to us, Huxley is demonstrating how much a society's ideas of 'morality' can change. Once, abortion and divorce were considered distasteful and immoral. In today's society, the two are much more common.

abortion rate
Public Domainabortion rate - Credit: BBC
Patrick Devlin wrote in "The Enforcement of Morals" (1965): 

"Societies disintegrate from within more frequently than they are broken up by external pressures. There is disintegration when no common morality is observed and history shows that the loosening of moral bonds is often the first stage of disintegration, so that society is justified in taking the same steps to preserve its moral code as it does to preserve its government... the suppression of vice is as much the law's business as the suppression of subversive activities."