You know, people who lack the ability to connect with others may have a some emotional detachment issues.
That's right. Emotional detachment is the avoidance of emotional connections. That sounds like a lonely condition.
Very much so, as well as a means of coping with anxiety by avoiding certain situations that trigger it.
It can also be a reaction to a chronic condition such as depersonalization disorder. It is definitely a coping mechanism.
Traumatized people subconsciously mutes their emotions in order to protect themselves resulting in the socially withdrawn behaviors.
Depersonalization is a condition where people feel detached or disconnected from themself. I would hate to have that condition.
 There are many causes of emotional detachment disorder and it manifests differently for everyone. 
True. People have it to maintain a sense of boundaries and psychic integrity, as well as avoid undesired impact on others.
A lot of people don't stop to take it into consideration why some people don;t keep in touch and don;t ever gert out of the house. This is a great example of actions (or lack of) affect the individual as well as those around them.
Emotional detachment
In psychology, emotional detachment is the inability to connect to others on an emotional level, as well as a means of coping with anxiety by avoiding certain situations that trigger it. It refers to the evasion of emotional connections. It may be a temporary reaction to highly emotional circumstances or a chronic condition such as a depersonalization disorder.
Emotional detachment can be a positive behavior which allows a person to react calmly to highly emotional circumstances. Emotional detachment in this sense is a decision to avoid engaging emotional connections,
, dissociation, depersonalization or in its chronic form depersonalization disorder. This type of emotional numbing or blunting is a disconnection from emotion, it is frequently used as a coping survival skill during traumatic childhood events such as abuse or severe neglect. Over time and with much use, this can become second nature when dealing with day to day stressors. 
Emotional detachment may allow acts of extreme cruelty, such as torture and abuse, supported by the decision to not connect empathically with the person concerned. Social ostracism, such as shunning