Student or Learner
(Tell me your intuition, thanks):
In order not to die, all mistreated children must totally repress the mistreatment, deprivation, and bewilderment they have undergone because otherwise the child's organism wouldn't be able to cope with the magnitude of the pain suffered. Only as adults do they have other possibilities for dealing with their feelings. If they don't make use of these possibilities, then what was once the life-saving function of repression can be transformed Into a dangerous destructive, and self-destructive force.
It's hard to say, bu I think it could be a younger speaker too as there is a mix of styles between formal and less formal, though this would be OK in some contexts. It's fluent, but should there be contractions and shouldn't there be a comma after 'dangerous'?