Jose is a homosexual man. Which of the following is most likely to be true?
A) He has a higher-than-average number of older brothers.
B) He has a higher-than-average number of younger sisters.
C) He is an only child.
D) He is a first-born child.

Question

Quizplus · Accepted Answer

Research has shown that homosexual men have a higher-than-average number of older brothers, known as the fraternal birth order effect. This effect is thought to be caused by changes in the mother's immune system response with each male pregnancy, leading to prenatal hormonal differences that may affect sexual orientation. There is no evidence to support the other options.

Jose Is a Homosexual Man