There has been a rising public interest in the methods employed by certain personality types to manipulate the people around them. People are rightly afraid that there might be someone in their life secretly controlling their decisions.
There are many manipulation techniques and are utilized most often by psychopaths, psychopaths, narcissists, and other anti-social, aggressive personalities.
The tricky and consistently fake social projections these types hide behind make them very hard to identify. Constant vigilance and a questioning attitude can be tiring but it is necessary.
Gaslighting is one of the scarier ways that someone can control another. In it the manipulator seeks to dissolve the victim's faith in their own judgements and perceptions. When successful the victim doesn't trust their own opinion or perspective. It comes from a 1930's film 'Gaslight'. In the film a husband attempts to drive his wife insane by subtly changing her environment and claiming that nothing is wrong or changed.
This can be done in several ways. In one method, a person can state a lie or opposing view so assertively that the other person doubts their original thought. If confronted about the discrepancies seen the scheming party can upset the victim through self righteous indignation. The disbalance of information coupled with the guilt of accusing or offending the manipulator can be enough to convince the victim of the lies validity.
The trickster can subtly tweak the minute details of information or past events so everything seems correct. They change just enough details so it serves their purpose, leaving enough valid information as to be hard to spot. Gaslighting is often paired with emotional manipulation such as shaming and guilt.
These personality types need to have advantages over the people around them to feel powerful and in control. Without an advantage they feel extremely weak and uncomfortable. They will do anything in order to disadvantage whoever they can.
The reasons behind this deceit varies from person to person. The end goal of these distortions are again varied and specific to the person. It stands to reason though that a person capable of justify the control of another person is out only for this best interests.
Through gaslighting a person can be led to loose their individuality and personal strength. Once they can't believe what they think or feel, they are completely at the mercy of their attacker. They will believe whatever their master says and do what they order.