I've been pondering this, you see. I notice in moments of crisis, it's almost like I switch off the emotion chip. Others have noticed this in me too, but it has to be a big crisis, where emotion is so intense, it would be crippling (system overload perhaps?). It also happens in routine, but relatively stressful situations at work also.
Emotional detachment occurs for me in situations involving other people where I a) feel awkward or b) feel ineffective, because it is the only way to avoid uncomfortable feelings.
When dealing with personal emotional crises, I often experience panic attacks, downward spirals of depression, guilt and self-loathing, and then instead of detaching entirely, I cover these up with different emotions that I know how to deal with, because I still want to avoid uncomfortable feelings. I only recently, in the past year, discovered what exactly I was doing. When I'm hurt, I lash out in anger, because I know how to be angry and throw insults around to whomever is associated with my emotional crisis. Or rather, whomever I feel has some part in it, even though it has much to do with my perspective.
So yes, I suppose I can say I have had the tendency to detach in a way from exactly what I was feeling in these moments, and I have learned to address these emotions more often, to acknowledge them, tell myself it is okay to feel this way, and then move on to checking in with myself on all levels, including physically, since a large aspect of emotions is physiological response. Much of my detachment has either had to do with ignorance of my true feelings or with anxiety over sharing what I know to be my true feelings with someone I care about and do not wish to hurt.