I don't know if we can change our attachment style as it is rooted in our infant behavior which has some of our personality we were born with, in there too. But we can change our behavior and I try to do that when I'm feeling anxious or detached and don't like the behavior I'm exhibiting.

Here's a good article on how it all fits, child to adult:

http://www.psych.uiuc.edu/~rcfraley/attachment.htm