I think it that the attachment style depends on the parenting style. I believe that the attachment style of a child can be an indicator of future lifestyle not because of the attachment style itself, but rather because of the reasons that attachment styles are formed. It has been shown that children of mothers who are depressed or neurotic are less likely to develop a secure attachment style. If, in the future, these infants grow up to be children with some developmental problems, rather than pin it on the fact that they did not have a secure attachment style, but rather on what caused that attachment style to come about.
I agree that parenting style affects the attachment style of a child. If the parent doesn't spend enough time with a child early on, the child is less likely to be attached to any adult because they felt like they couldn't really trust their own parents.
