I've been fascinated by attachment styles ever since my psychologist and I discussed my avoidant tendencies and the impact they have on my relationships. Honestly, it's an adaptation as much as it is a problem for me - thanks to consistent therapy and introspection I've been able to find a balance between my "aloofness" or as some friends have affectionately said, my "ice queen tendencies," and my deep, abiding love and loyalty towards the people I care about.
It's not always easy to find that balance, but if you really love someone you'll work to find ways to change your harmful behaviors and make them feel cared for. It's very hard to do that, but I truly believe it's a matter of moral priorities and empathy. If you're naturally selfish, though...well, good luck to the people who care about you :|