The countries with larger proportions of 10-year-olds in their populations are poorer than those with relatively smaller proportions of 10-year-olds. While they share the same chronological age, there is tremendous variation around the world in the ways they live their lives, with significant implications for both their own future and that of the planet. This section examines some of the key components of their lives, focusing in particular on the areas where clear patterns emerge. The situation is particularly acute in countries that have recently experienced significant upheavals such as war or natural disasters.