Some of the characteristics that the book associates with having a good well-being can easily be acquired through superficial means. For example, popularity and positivity(happiness) can easily be attained, especially for little children, through the gifting of something that they deserve and others envy. In terms of empathy and serenity, (i.e. freedom from anxiety disorders) , I feel as though these qualities are things that can be learned through experiences and interactions with other people.
I see what you are saying... In regard to popularity and positivity do you think that may be a self-fulfilling prophecy? Or even a confound? I think back to the "what is beautiful is good" perception. Say for example someone is particularly physically attractive. They are often times more popular and socially skilled because people are more willing to engage with them, thereby giving them more opportunities to develop their social skills. In this case it could be seen as the anxious/avoidant child not being unable to develop social bonds, but rather not being afforded the opportunity to do so.
I don't agree that popularity is easily attainable. Social interaction is complex espcially for a child who is interacting for the first time. Often times children find it hard to read the emotions or intentions of others. For example if Sam intiates a game of make believe and asks John "Do you want to pilot the plane or the helicopter?", all too often John will choose one without thinking twice. A child with a higher intuition of socializing will pause and ask Sam "Are you in the plane or helicopter?"
I do agree however that these social skills are highly influenced by experience. However a securely attached child may be more willing to gain social experience at least in the early stages which means they do have a head start.