Well, we are talking about psychological manipulation here so here is a description on Wikipedia (link!).
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Psychological manipulation is a type of social influence that aims to change the perception or behavior of others through underhanded, deceptive, or even abusive tactics. By advancing the interests of the manipulator, often at the other's expense, such methods could be considered exploitative, abusive, devious, and deceptive.
The positive variant of it, even though it still can be used for manipulative purposes:
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Social influence is not necessarily negative. For example, doctors can try to persuade patients to change unhealthy habits. Social influence is generally perceived to be harmless when it respects the right of the influenced to accept or reject it, and is not unduly coercive. Depending on the context and motivations, social influence may constitute underhanded manipulation.
I ocassionly use my social influence to get things done at people, I'd be a good manipulator if my principals weren't in the way

. Can do 1 and 2 - 3 on the other hand is a bridge to far.
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Requirements for successful manipulation
According to Simon, successful psychological manipulation primarily involves:
1. manipulator concealing aggressive intentions and behaviors.
2. manipulator knowing the psychological vulnerabilities of the victim to determine what tactics
are likely to be the most effective.
3. manipulator having a sufficient level of ruthlessness to have no qualms about causing harm
to the victim if necessary.
Consequently the manipulation is likely to be covert (relational aggressive or passive aggressive).
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