To lose something or someone close to you is a trauma at any age. The younger the mind is, and the less experienced, the more severe the effects of the trauma. Holden lost his brother Allie to leukemia. Holden would be the middle child after that loss, leaving him the most vulnerable. His older brother D.B was old enough to accept the terrible events and cope with them. His younger sister Phoebe was too young to have a concept of what was going on around her at the time. This left Holden: young, confused, angry and alone. "I was only thirteen, and they were going to have me psychoanalyzed and all, because I broke all the windows in the garage." (38-39). Thirteen years of age is just beginning the adolescent years - a time of maturation and change, but also a time of great confusion.
A Freudian theory many of us in the medical community are familiar with is the theory of defense mechanisms. This theory describes different actions the mind has been known to do in response to a trauma. If I were to pinpoint a mechanism here, I would have to say it is a form of Regression. Regression as you know is the return to a state of mind to a time of happiness and security before a trauma. Holden experiences this in a different way. He is developmentally FROZEN at the age of 13. It is as if he were walking