The Silent Treatment is perhaps the worst sort of emotional abuse that can be inflicted on a person and also one of the most widespread. There is an excellent short article on the subject available on The Atlantic, including a great deal from Purdue psychology professor Kipling Williams, who has studied the behaviour for more than thirty-five years. He notes: "People use the silent treatment because they can get away with it without looking abusive to others and because it's highly effective in making the targeted individual feel bad." There is an enormous problem here because the victim literally feels the same pain as physical pain but because it has not been expressed, they do not exactly know why they're being punished. It can be so devastating that many victims, especially those in co-dependent situations, have expressed that they would prefer directed rage or even physical violence in preference to The Silent Treatment. Tragically, if there is a genuine grievance, The Silent Treatment is profoundly ineffective for the perpetrator as well, as they cannot achieve a resolution because it is never stated with clarity. It is, in a nutshell, a hurtful and abusive act of self-sabotage on their part.
Ironically, the common objective of using The Silent Treatment is passive-aggressive attention-seeking by those who are manipulative and cruel but also lacking self-esteem and confidence. Is often carried out by people on the spectrum and continuum of "Cluster B" personality disorders. Narcissists, with their own fragile sense of self and projection of their own insecurities, employ it as a manipulative tool of choice. People with Borderline Personality Disorder ("The borderline is nothing more than a failed narcissist", as quipped by Grotstein) will also employ it, albeit usually with a different motivation. In "Quiet BPD" cases instead of inappropriately confronting a person with an unjustified rage, they will avoid, withdraw, and shut down. This often results in friends and loved ones abandoning the relationship, which becomes self-justifying in the mind of the person with BPD as an alternative to recognising and dealing with their own empathic incompetence. In both these cases explanations are always meant for understanding, rather than an excuse. There is a victim and an abuser here, and the abuser is the person who carries out The Silent Treatment.
For the victim of The Silent Treatment, there is often a desire to end the pain, for which there are right and wrong approaches. A loving approach would express a desire to repair the damage, seek clarification on what can be done, and work on resolutions. Whilst the victim may feel they need to apologise, they must not do so if they've done nothing wrong - it may bring temporary peace but it only acts as a negative reinforcement to the abuser that they can engage in this approach again and again. It can also be valuable to explain to the abuser that the behaviour is not acceptable, that it is hurtful, and not conducive to a working or worthwhile relationship. This approach works particularly well if the perpetrator is acting primarily on the basis of confusion and fear rather than malice, and boundaries of conduct within the relationship can be established. If neither approach generates an appropriate response, the best thing for the victim to do is to continue their own lives - depriving the abuser from the reaction they want and building the self-esteem of the victim. This must be distinguished from responding with The Silent Treatment from the victim; if the perpetrator shows that they genuinely want to engage and resolve things there is great harm in reversing the roles. It is important never to respond to The Silent Treatment with anger which will escalate the situation.
All this said there are times when going silent on someone is thoroughly justified. One example would be when a red line is crossed, such as physical abuse, it is quite justified to cut a person off. The Silent Treatment should not be confused with a "time out" period, such as after parties have engaged in heated disagreement and need a bit of time cooling off. This is best done with a request for some specified time and space to gather thoughts. However, outside of these exclusions, an instance of The Silent Treatment is abusive in itself, regardless of intent, even when it comes from a confusion and fear within the perpetrator's own mind. Whilst there has been discussion of how victims can effectively respond to The Silent Treatment, it is absolutely critical that the perpetrator takes into account and ownership of their behaviour as well, otherwise they will simply continue to harm others and fail to achieve what they really want. As the aforementioned Atlantic article concluded: "In the end, whether it lasts four hours or four decades, the silent treatment says more about the person doing it than it does about the person receiving it."