The team then looked at family size and birth order in both groups.

This study found no relationship between birth order and intelligence.

Larger family size and later birth order are also associated.

To indicate a person's position in the family, also known as birth order.

It was strange how birth order had made them so different.

Boys had a greater chance of being kept alive as the birth order increased.

Why do people believe that birth order has important effects on personality?

Other studies of different age groups have shown that birth order can be a factor.

In 1988 and 1989 there were 45 scientific reports on birth order, more than a third of which found it had no effect.

This article is about the musician, for the birth order see Only children.