In comparing the birth order of gay men to heterosexual men,it was found that
A)gay men were more likely to be only children.
B)gay men had more sisters than heterosexuals.
C)gay men were more likely to have had a late birth order and have a number of older brothers.
D)gay men had more brothers and had an early birth order.

Question

Quizplus · Accepted Answer

Research has found that gay men are more likely to have a later birth order and have a number of older brothers. This is known as the fraternal birth order effect and is thought to be related to changes in the mother's immune system during pregnancy. There is a weaker correlation with having more older sisters as well. There is no significant evidence supporting the other options.

In Comparing the Birth Order of Gay Men to Heterosexual