I think that attachment is a large factor when it comes to development of a child. However, I believe that other stressors that occur naturally when growing up have a factor on the child as well. These can include anything from low aptitude to violence from peers or from parents. Low aptitude can create frustrations internally when one cannot works as well as classmates. Violence is much more external as pressure from peers away from attachment to parents
I agree with you. Relationship with parents later in life and also influences from peers can be major factors of stress that can change a child's development. I haven't thought that much about the factor of violence, but I think that indeed, it is significant in its effect on children. Also, these emotions of frustration and fear from violence can indeed be major influences on child development.
I agree with you on both your conclusion and your ideas of the influence of violence in early childhood, however, I am not so sure I agree with the lower aptitude assumption.
I believe that whether a child is brilliant or not so smart is actually dependent on how the child is raised. In that I mean that secure attachment affects aptitude, so if aptitude does affect a child's well-being, then in reality, the attachment affects the well-being.
I agree with your argument that attachment is very important, but there are various other factors to consider when evaluating what type of a life an individual will lead. Factors such as external influences and the decisions that an individual makes for himself are equally important in determining the type of life that an individual will potentially live.