Studies demonstrate a largely correlational link between attachment style and well-being later in life. Another cause, or independent variable which may be largely influential in one's well-being in life (the dependent varibale) is certainly the environment. I feel that how one is raised (i.e. parental influence; culture; social and political subjection) truly effects the kind of person a child subsequently becomes. Perhaps leadership roles are encouraged by parents and accepted with gratitude by society early on-- this may lead to increased leadership or responsibility in the future.
I do agree with your statement, that the way a child is raised effects the kind of person he or she becomes in the future. Parents are indeed good role models, especially when it comes to leadership and responsibility. The environment the child is in influences the development and behavior of that child.
I posted something similar, but I believe my statements were only a subcategory of what you have summarized here. I do think how one is raised have a very significant impact on one's development. I see style of attachment kind of like a "starting point". Having a REALLY bad starting point would certainly effect one's path of development but I think, for most cases, it is all determined by how the path is formed, and can have similar outcomes even with different "starting point", and have different outcomes even with the same "starting point", etc.
I think other than just experimental factors one must also examine who the parents are. Abusive or non-interactive parenting would interfere with a child's ability to attach correctly. I like what you have said about environmental factors in attachment. I wonder what it will be like for all the soldiers in Iraq to come back to new born children that haven't met one of their parents yet. I wonder if these children will form attachments to their returning parent or have a stronger attachment to the one that was at home.