Boundary walls block all things, both good and bad from getting in or out. Often the result of psychological trauma, walls leave one relatively protected against stress, but also lonely and lacking social interaction.

As far as the character maturity of "boundary anatomy" goes, these items are midway between the lowest maturity anatomy (Boundary Holes) and the highest maturity anatomy (Boundary Doors.)  So they are then also midway between the two in level of narcissism.

These people tend to protect themselves, not by saying NO to others, but by being unavailable, by hiding or isolating, or alternatively, finding ways to generally have it be known that they "say NO to everything" others ask of them. And as a result they may seem like "loners," when in fact, they would love to have connection to others.

They are being self-protective. As a result, Boundary Walls might be thought to develop out of the experience of Psychological Trauma in life.  They are then adaptive in a way, in that they protect the individual from being taken advantage of, but they are maladaptive in that such people are culturally cut off from others and from love. They may end up feeling "lonely and hungry" if they employ this boundary anatomy as their dominant type.

These people may be said to lack Intimacy and to be overly Independent as a partnering style, and social mode of being. This is better than being codependent, but not as mature, happy or successful as a partner, as an interdependent person is.