I've noticed it my family. My wife has a much easier time talking to our two boys, while I find it MUCH easier to talk to my daughter.. . The relationships are blatantly different. I suspect it carries over generally to many families.. . What I notice with my daughter is "pre-flirting" behavior. I'm not sure what else to call it -- it's flirting without the sexual component. She sort of views herself in competition to my wife for my attention emotionally, she loves to dote on me and play around in conversation, and so forth. . . I feel like she is unconsciously "practicing" for how to relate to a guy when she gets older. Also, she is looking for affirmation that she is desirable and someone I want to be with. She also loves it when I do things that show how "strong" I am -- picking her up, swinging her around, and so on. The boys like it as well, but more in the "play sense" -- where she seems to be emotionally affirmed and feel more secure as a person by knowing I am strong enough to take care of her, and that she's safe here.. . My wife really nurtures the boys, and they like to be affirmed and feel secure knowing that they have a safe place to go to, where their needs will be met, after the stresses of the day. It's like they use her for a secure haven from which they can venture out, then come back later to refuel.. . I hate to compare it to "romance" because that has negative connotations, but there's nothing sexual about it -- it's like all of the emotional aspects without the sexuality. I love her, I think she's beautiful, I love to be with her, I love to take care of her and enjoy it when she feels safe and valued. I protect her and am strong for her. . . While I love my boys as well and do those things for them, my relationship tends to be a little more impersonal and doesn't feel quite the same way.. . Sorry I can't quite articulate the feelings, it's hard to put into words.