USA - Passive Aggression is often defined as
learned helplessness,
procrastination,
stubbornness,
resentment,
sullenness, or deliberate/repeated failure to accomplish requested tasks for which one is (often explicitly) responsible.
A recent study performed at The Research Center for Healthy Assertion (founded 1981) was performed due to a noticeable rise in cases of Passive Aggressive (Negativistic) Personality Disorder. The study revealed that Passive-Aggression is actually, quite simply another form of aggression. In addition the researchers uncovered that the effects on the victims of Passive Aggression include defensiveness, anger, hostility and a feeling that they are being manipulated.
One case study stated, that those participating in passive aggression often feel that they are not being hostile and when met with returned aggression become angry and feel that they are being treated unfairly. On the other hand many of the study participants reacted in a somewhat antagonistic manner when passive aggression was tested on themselves.
Sherry Urbane - Director of the PAPD Study - commented that her findings were conclusive, though they warrant further study. The reports indicated that Passive Aggression was nearly completely ineffective as an interpersonal tool, often damaging to relationships and was not a healthy way for one to assert oneself. Sherry feels that this disorder has not gotten the attention that is warranted and hopes to help those afflicted to come to a better understanding of their emotions through her study.
For a detailed description of PAPD see the Medical Manual DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL DISORDERS aka DSM-IV-TR®.