I recall a TV program some months ago, discussing just this issue concerning China. China's one child policy was started in 1978 (with a few exceptions for certain circumstances).
China now has an entire generation where most/many of the population has no brothers, sisters, cousins, aunts or uncles. It is a difficult concept to contemplate.
God only knows all of the implications of this. Even on the very mundane and simple level, it could lead to a very self-centered society. Most kids first experience of sharing and compromising takes place when dealing with their siblings. Without siblings, how do they learn to share and compromise? And with only one child per family, there will likely be much more of a problem with spoiled kids... being showered with all sorts of things that they would otherwise have to share with other family members. I suspect that we should be seeing the results of this right about now (in China), as all of those first "one-child" kids are now adults.
Maybe Italy can study the results of this course in China, and make some changes before sooner rather than later.