While attachment types and well-being later in life is correlational, it's not necessarily a causal relationship.
Another possible explanation that could be taken into account could be the person's natural tendencies or perhaps how they can relate to people. Maybe as a child, the person is very friendly and easy-going thus making it easier for the caregiver to care for them and form this secure attachment and healthy relationship bond. This naturally friendly tendency could carry on throughout the person's life, giving them more opportunities, greater connections with others, and overall more happiness and a higher well-being.
That is true. Attachment theories are not necessarily causal, but since they occur at such a developmental phase in life, I feel as though they can be causal in babies. Introducing an adopted child, for example, is different because the child may have already developed a different view of parenting and thus will not comply to a secure attachment method.
I agree that this is not necessarily a causal relationship. I also agree that internal tendencies can impact their well being. Also, their environment outside of their relationship with their parents will impact their well - being later in life.
