China's notorious one-child rule, which limits couples to only one child in order to keep the world's largest country's population in check, may be unraveling. While families once grew up with propaganda posters warning that "Mother Earth is too tired to sustain more children" and "One more baby means one more tomb," China's policy has cut the birth rate to 1.8 per couple from six when the policy took effect over three decades ago, creating new problems as the population ages too rapidly. Officials are concerned that a flood of retirees will tax the country's benefits system, much like in Japan or America as baby boomers enter their golden years, and that China's per capita wealth will be insufficient to adequately take care of them. As a result, exceptions are being made to the rule, including allowing urban families to have more than one child. But couples used to the one-child system may be reluctant to switch with little model for how to raise large families. "We have already given all our time and energy for just one child. We have none left for a second," one mother told The Washington Post.