Question

what statement below about the older brother effect is false?
for each additional older brother a right - handed male has, his likelihood of being gay increases by about one - third.
it appears to be due to a biological factor, because the trend is not observed among adopted brothers.
the trend might be caused by the mothers immune system treating proteins in the male dna as foreign invaders, and creating antibodies to attack them.
it could occur because younger children tend to receive less attention from their father due to each additional older brother.

Explanation:

The Older Brother Effect is a biological phenomenon. Research shows that for each additional older brother a right - handed male has, his likelihood of being gay increases by about one - third. It is thought to be due to a biological factor (not seen in adopted brothers) where the mother's immune system may react to male DNA proteins. There is no evidence to support the claim that it occurs because younger children receive less fatherly attention due to older brothers.

Answer:

It could occur because younger children tend to receive less attention from their father due to each additional older brother.