The position a child occupies in a family, based on arrival and number of other children, such as only child, first-born, second-born, middle child, youngest, and so on. Traditionally, many people have believed that birth order has a strong influence on a child’s development and personality. Theories abound, such as that first-born or only children are strong, self-directed, capable leaders; second-born or middle children are more relaxed, spontaneous compromisers; and third-born or youngest children are more gentle, passive, withdrawn followers. Some assert that first-born or only children tend to support the status quo, while second and later children are more likely to challenge established views. Though popular, such views are highly controversial. Some studies tend to support influence of birth order on personality, but critics charge that supposed influence of birth order often turns out, on closer analysis, to actually be due to other factors, such as the family’s social and economic status, educational level, or age.
Sequence of births among siblings; one’s position in the sequence is believed by some psychologists to affect learning ability, intelligence, and the development of personality.