Interesting stuff. Everybody has at least two points in their lives at which they are vulnerable: childhood and when they become infirm with old age. I'm getting elderly, such that this subject puts me at attention. I enjoy the fact that we study vulnerability and defenses; it is imperative that we respect elders, realizing that values shift with age. What is important in younger years may changes as life span shortens.

Thank you for citing sources and presenting this information in a straight forward manner.Life is important stuff.