It is hard to define who a child is, and that definition has changed over time. Throughout history you had kids at very early ages who took on an enormous amount of responsibility, caring for their families, going out to work, getting married very young. It was not so long ago that in this country girls got married regularly as young teenagers. But as we have industrialized, as we become a wealthier nation, and as the world is becoming wealthier, that age of maturity has gone higher and higher.
Physical development is an important and obvious marker. But it’s not just physical maturity. There’s also emotional maturity and the ability to truly develop the skills one needs to assume the responsibilities of adulthood. In my community, you become an adult once you’re circumcised, whether you are nine years old, whether you are ten years old, whether you are 13 or 14. Once the cut has been done to you, that symbolizes that day and that minute that now you are an adult so you can do anything an adult can do. If it’s giving birth, if it means getting married off, you can do anything. You are now considered an adult.
The distinction between childhood and adulthood has changed very quickly in a number of societies as life expectancy increases, as economic development is defined much more in terms of brainpower than it is in terms of simple strength. Take Afghanistan for example. Over the course of the last twelve years, life expectancy in Afghanistan has increased for girls from 47 to 60 years in just a decade, and along with that is a recognition that the need to empower girls to contribute throughout their lives outweighs any short-term advantage to a family or to a community from simply marrying off their children.