Since most borderlines did not have their needs met in the developmental years there is a propensity toward negative perception. This negative perception is aroused and or triggered by any number of things that take borderlines emotionally back to the unmet needs and the pain that sits there until faced, felt and healed.
Devaluation is the lessening of someone or something.
It often results from triggered-distorted thinking. It is yet another facet or extension of borderline-narcissism. When one begins this cycle of devaluation there is great reason for concern. It is a slippery slope from the mental exercise of devaluation to behavioural reality of aggression or passive-agression. When one is devaluing another person who that person is gets blurred.