I believe that secure attachement to a caregiver and a child's well-being later in life are positively correlated with each other. This is the first relationship that a child will have and it will have a great influence on how the child approaches relationships in the future. If the child is able to develop a secure attachment to their primary caregiver they are more likely to feel comfortable and open to approaching new friendships and relationships outside of their family, something that is needed in order to become a well-functioning part of society. However, I do believe that this is just the first step towards developing a child's future well-being because there are many other factors that will affect the way the child perceives the world and their relationships. The biggest one of these factors is their environment, which includes their primary caregiver. This does mean that even if a child was able to develop a secure attachment to their primary caregiver, their environment may still be able to have a negative impact on their future showing that secure attachment does not guarantee a better well-being.
I agree that the environment can still make a negative impact on a child's future despite a secure attachment. You bring up a good point about the fact that a child's first relationship is with the primary care giver. If the child fails to establish this relationship than it is possible that no matter how nurturing the child's future environment is, the child will not be able to forge any other relationships. This would have a severe negative impact on the child's adjustment and he or she would have to work very hard to overcome such an obstacle. In such a case pursuing a normal life could be impossible.
I also agree with May. Secure attachment and later life well being are correlated but these two attributes are not the single cause and effect. Environment as well as a number of other developmental factors heavily determine how the individual will be later in life.
