Claudia, not that we need to get technical or anything but are you thinking of "natural affection" (part of the sign of the last days) as the NWT terms it? I suppose it goes back to the double standard thing, the brothers are trying despite being imperfect but people in the world are wicked or what have you.
Actually I think the distinction is important. If I had to look at myself in the area of romantic love, for example, I can't say that I really love every woman I'm attracted to. In fact, if that's all it is it's really a self centered thing on my part. In one sense I love all human beings, but the fact I'm sexually attracted to this person it just means I still have a little bit of hormones left, though I do think there is a feeling that's different in quality when you really love someone who you think is special. I suppose you could say both kinds of love is natural, but the fact I feel sexual attraction doesn't make me a special person..
"Knowing others is wisdom. Knowing the self is insight. Mastering others requires force. Mastering the self requires true strength." -Tao Te Ching, Chapter 33