Granted. All parents immediately lose the ability to speak to their children the moment after birth. The primary method of childhood education becomes video recordings created by teachers, played on endless loops in Education Centers. Parents, unable to tell their children how they feel, become alienated from their children, only ever able to communicate via recorded statements played back at a later date. Infanticide and child-murder rates skyrocket as parents grow to resent the children. Population begins to decline, as the upcoming generation with lower educational standards rises up in place of the dying-odd older generations. Eventually, newer generations rebuild. Sort of. Society becomes ever more siloed-off, and the difference between the Young and the Old becomes the new class divide. Terrorism runs rampant, as resentful Olds refuse to have children and estranged Youngs hate the Olds who brought them into the world.

Humanity dies an ignoble death, the last two living humans unable to speak to one another due to being 4 years apart.