The Free Child ego state in us is constantly moving between desensitised, sensitised and hyper sensitised depending on the environmental circumstances. When we are confronted with stimuli that is distressing to us in some form then the FC will automatically draw away in an effort to protect itself in the future. This results in desensitisation and happens in us automatically.
If the sensitive, vulnerable part of us (FC) is confronted in some way then it will automatically assume that the same is going to happen again in the future so it draws away and hides. And this is what we call desensitising. The young man goes to war and sees the first mangled dead body and he is highly distressed. After he has seen six of them he hardly even notices the body as he walks by. The FC is hidden away so the distress is reduced.
See these three images.
In non distressing environments the FC is available to the person
In more distressing environments the FC starts to hide away
In very distressing environments the FC can split off and the person dissociates
However it also works the other way. If we are in an environment where we have little confrontational input then the Free Child will assume that is going to continue and it will come out more and more so we become hyper sensitised. As we become hyper sensitised it takes smaller and smaller negative images or confrontations to make us feel distress. If therapy rooms become more and more safer and less and less confrontational then clients will become more and more hyper sensitised and smaller and smaller objectionable material will make them feel distressed. In this sense they become more vulnerable.
If one is desensitised then they are more ‘tough’ and are less vulnerable in this way. More capable of handling distressing images and situations in life. However this only works in the short term. One cannot live without good access to their Free Child for long periods of time without beginning to suffer in some form. Such suffering can include excessive drinking, anxiety, depression, insomnia, relationship failure and so on endlessly. Being desensitised for too long will result in symptoms developing in some form. We all have to have some kind of access to the Free Child part of our personality at least from time to time to avoid such conditions developing.