Tone-policing is a diversionary tactic which answers a legitimate argument by observing that the arguer is clearly upset, thus diverting the topic away from the substance of the argument and on to the subject of the arguer's mood (often stated as some form of anger).
It can also take the form of arguing that the speaker should use calmer, less extreme phrasing in order to avoid driving off the audience. (Note: It may be that this is what is always meant by "tone-policing", and the other form of argument really should revert to its original label of diversionary appeal to calmness.)
Issuepedia originally (2009) described this as "appeal to calmness", with a note that there are circumstances under which appealing to calmness is legitimate. The term "tone-policing" emerged in the interim (not sure exactly when, but it was well established by 2015.
On further thought, given the two possible interpretations of "appeal to calmness" we have decided that the formal term should be "diversionary appeal to calmness" in order to distinguish the diversionary tactic from legitimate calls for de-escalation.
Tone-policing can be especially effective if the arguer is actually upset in some way, as the discounting of the argument may successfully push the arguer "over the edge" into a truly irrational (possibly even contemptible) display of anger, thus further undermining of the arguer's credibility and making the "calm" responder appear reasonable and sane by comparison.
Tone-policing is related to a number of other diversionary tactics:
- It is a form of ad hominem attack in that it responds to the argument by undermining the arguer's credibility.
- It is an appeal to emotion in that it operates on emotions rather than on the substance of the argument.
- It is a combined argument by ridicule and appeal to guilt, as it may make the argument seem ridiculous by making the arguer (and hence the arguer's motivations) seem ridiculous; it also subtly implies that the arguer is irrationally overreacting and that their arguments are irrational as well.
- It is a key element of the highly annoying style of personal discussion now known as "sea-lioning".
- It is in some ways the mirror-image of concern trolling. Where a concern-troll will say "I find X upsetting, [why] don't you?", a tone-policer is effectively saying "let's talk about how upset X clearly makes you". On the other hand, some concern trolling focuses specifically on trying to "improve effectiveness" of an activist community by focusing on its "presentation", i.e. tone – which would be both concern-trolling and tone-policing.
Tone-policing is distinct from a legitimate appeal to calmness, which attempts to quell emotions that are actually interfering with rational debate (as opposed to being used as an excuse to create such interference).