Women who have had consecutive boys in the past are more likely to have a boy next time than those who have had only girls.Hamamatsu University School of Medicine Specially Appointed Lecturer Shuhei Sou, Director of the National Institute for Environmental Studies Shin Yamazaki Research Core Center for Eco-Children Research, and others examined data from national surveys on children's health and the environment, and came up with the following results.
According to Hamamatsu University School of Medicine, out of about 10 participants in a national survey on children's health and the environment, So and his colleagues targeted about 6, excluding those who had miscarriages, stillbirths, or abortions. We investigated the relationship between the sex of the offspring and the sex of the offspring's siblings.
As a result, the probability of having a boy for the first child was 1 for one girl, but when looking at the second child, there is a slight difference of 1.055 if the first is a boy and 2 if the first is a girl. I found out.
In the case of the third child, the probability of giving birth to a boy increased to 3 for those who gave birth to only boys in a row in the past, while it decreased to 1.112 for those who gave birth to only girls in the past.Furthermore, the probability increased to 0.972 for three consecutive boys and to 3 for four consecutive boys.
A statistical analysis of these results shows that women who have had consecutive male babies in the past have a 7% higher chance of having a boy next time than women who have consecutively given birth to girls.
Paper information:[PLOS ONE] Pregnancy bias toward boys or girls: The Japan Environment and Children's Study
