>>40645961
>>40646003
the point is that past a certain number of children, it's more valuable to take better care of your children rather than have more. If you already have 4 or 5 children, you're passing on your genes multiple times. If your 5th child is homosexual that means they can function as a potential third or foster parent to your grandchildren, or provide support in other ways.
Having a lot of children is evolutionarily good, but putting resources into extra children that you can't take care of is wasteful, and can in nature result in starvation. Counterintuitively having a generation with slightly more adults and fewer children could increase stability of the society and ensure better odds of genetic survival than simply having as many children as possible, as humans are extremely energetically expensive to raise, being highly K selected.
the fraternal birth order effect observes that as the number of older brothers increases, the odds of being homosexual also increases. So it seems that genes that actually limit the upper rate of reproducing males are fairly successful.