Negative stereotypes are attached to childless or 1-child couples and to only children. People choosing to have fewer than the socially predicted 2-child norm are responding to rational, individual norms instead of exterior normative pressures. Research has shown that only or widely spaced children benefit from adult contact during development. There is an inverse relationship between intelligence and family size. Only and 1st-born personality characteristics tend to contradict the negative stereotypes. Different reasons why couples choose to have children do not differentially determine the health of the children or the marriage.