Tested on people: surprisingly, but the fact - almost all future fathers want sons, and then for some reason they love daughters more.
............
I will be embarrassed, but I will answer:
The sons want because of the stereotype: "inheritance", " to pass on the surname", "marriage" (about the father of the girls)
And girls are more affectionate, manipulate better and cause big subconscious erotic experiences. Freud, shit what are you doing?