Sex, age and racial composition of the world’s population
By age structure the population is split into three groups: children (0–14), working-age people (15–64) and the elderly (65 and over). In many countries of Africa and Asia the share of children is large (Niger, Mali, Uganda), while in Europe and Japan the share of the elderly is large. In sex structure, men and women are nearly equal worldwide; Europe and North America have slightly more women (who live longer), while parts of Asia and the Gulf states (because of labour migration) have more men. An age-sex pyramid shows the share of each age group for men and women: it is broad-based in young populations and narrow-based in ageing ones. Races are groups formed in ancient times by adaptation to the natural environment, distinguished by outward traits; the traditional classification names four main races – Europeoid, Mongoloid, Negroid and Australoid – plus intermediate and mixed ones. Mestizo, mulatto and zambo groups are common in the Americas. Scientifically, all people belong to one species (Homo sapiens), races do not differ in ability, and racism has no basis.
“Draw the pyramid”: two groups sketch rough pyramids for Niger and Japan by age groups (0–14, 15–64, 65+) and explain them to the class.