The level of attachment that an individual has as a child is not the only entity that influences their well being later in life. Another factor could be the type of environment that they grew up in. A child could have grown up in a healthy environment with loving friends and families around them and they will tend to have a higher well-being later on in life. However, there are also some cases in which a child has grown up in a negative environment, around individuals who do the "wrong" things. In rare cases, the child growning up in such a negatively influenced environment can devote his life to being the complete opposite of what he/she sees. They may have some scars from the past, however, their efforts to do the "right" things will influence their well-being.
I agree with alternative factor. I think outside experiences/influences has a major impact on the development of a person. Even if the child did not have a secure attachment as an infant, but grew up in a positive environment, it is likely they would adjust well later in life. If the child did have a secure attachment as an infant, but later grew up in a negative environment, it is possible they would not adjust well later in life. The events they experience in these environments factor the well-being.
I completely agree that well-being is not entirely determined by the secure attachement. There are many other factors that could go into play to affect the chid's well-being. The environment, for example, could play a huge role in the child's well-being. It cannot just simply be based on secure attachment.
