Is Heartless the best policy?

Just had a conversation with an old friend over the phone, who's afraid she's too heartless for her own good. It made me wonder is heartless the best policy? do we as girls, allow ourselves to get too attached to hot blooded males who have one thing and one thing only on their mind. Ok so I'm not saying that every single male in the world is like this, I've come across a couple that aren't but every girl in my group of friends, seems to go for the type that will use you, and hurt you. Myself included. Its hard because its a strange kind of attraction, and its hard to avoid. So would it hurt to become a little bit more like them and would it better for us. I'm sure it would certainly spare the pillow a few tears, but is this the point when everything maternal about us kicks in and says no you do care and your supposed to care and its ok that you care? I honestly wish I could be a little bit more heartless and less attached to this arrogant, pig headed type of person I'm attracted to. Yet I can't  help to wonder if its a good thing being heartless, is it more or less attractive? Does society accept heartless women? or does it just throw them to the side and class them as spinsters, women that have been hurt so badly in the past they can't bring themselves to love again. Is it part and parcel of being young, were not looking for somebody to spend the rest of our lives with at the age of 20, so is it just a bit of fun that our emotions get too attached too? 
Laura 
xoxo