Birth Order (III) : Methodological Errors of Studying on Birth Order (2)

Abstract

There are numerous studies on birth order in psychiatry, psychology, sociology and other fields. In most of the studies the relationship between first-born and last-born has been argued. Reviewing the previous reports from the view point of Statistical Estimation, however, it was found that most statistical procedures by which they attempted to analyse the effect of birth order, erred in determination of the universe and sampling. In this paper, the author critizes these mistakes especially in sampling.