SYNOPSIS
There is available an extensive literature relating to birth order and its possible effect on the incidence of psychiatric disorder, on character, or on patterns of personality development. Little attention has been given to the distribution of sex within sibships. A study is reported on the sibships of 400 consecutive psychiatric admissions. The preceding sibships show an increase in same sexed members. This effect is most obvious in larger sibships and for the penultimate member. This may be due to a series of children of the same sex born into a family. Finally a child of the desired opposite sex is born and the family completed.