There are several variables that contribute to different trauma responses. 

Physical Proximity to the Actual Event

Those who were closest to the event likely to have a stronger response than those who were some distance away.

Previous Traumas

Some people may have had traumas of different types (physical or sexual abuse, accidents, medical traumas, neglect) in childhood and adolescence for which they may or may not have been treated. Such traumas can have a cumulative effect.

Availability of Support Systems

Some may not have readily available emotional support systems, may live alone or with only one or two others, or maybe physically far from home. Sometimes even close friends or family members may deny the depth of the experience and may urge to “Get on with life” or say “It wasn’t that bad.” This is demeaning to those who felt their lives or those of others to be at significant risk.

General Resiliency

Resiliency is the ability to bounce back from adversity and severe emotional stress. Some people have a natural capacity to do this and others have to cultivate it. In what is perceived to be a life-or-death situation a person may be totally overwhelmed in the moment and unable to respond without help or orientation from others.