It is now common knowledge that the world is greying. The elderly are increasing in number, and the birthrate is declining. The trend is universal, but not all nations are greying at the same time or at the same pace. This unequal greying is setting in motion a new social dynamic, idenitified by the author as "grey dynamic". Slender families, the breakdown of marriages, children with no siblings or cousins, and vanishing multi-generational homes are all symptoms of the future grey world.