Not so long ago, most people had large families: five children, on average. Where once there was one global fertility rate, today there are many, with differences wider than at any point in human history. Family size, whether small or large, is intertwined with reproductive rights, which are tied to many other rights, such as those to health and education, adequate income, the freedom to make choices, and non-discrimination. Where all rights are realized, people tend to thrive.