My parents have owned Golden Retrievers for years. We have noticed this with most of our dogs. They seem to just prefer one sex to another. After thinking about it for a while I thought maybe it had to do with the breeder. The dogs that preferred male companions were raised by male breeders. The dogs that preferred female companions were raised by female breeders. With my Yorkie, Alex, he was raised by a woman and he is definitely a “momma’s boy”. It’s just a thought….