ABSTRACT
The sizes of various age groups, male and female, are conventionally represented in what is called a population pyramid. For a demographic analysis the important classification of any population is one by age and sex, for which the term is population structure. A stable population with no growth is called stationary, and this is the meaning that demographers assign to what the antinatalists term "zero population growth." If efforts to reduce fertility focuses only on cutting the number of children per family, and if the number of families increases, the population will continue to grow. More American adults are putting away childish things and concentrating on prosaic matters as job security, family stability, the safety of their home and children, the taxes on their incomes and property. Both biology and culture set many differences between males and females, and often a distinction is made between "sex," related to physiological impulses and constraints, and "gender," the comparable effects of the culture.
