How we change what others think, feel, believe and do
Reversal tagging is a way of gaining agreement, gaining compliance or just always being right. It uses a structure that includes two opposing positions within one sentence, with the first being a statement and the second component being a tag question.
The principle is to make a statement and then add the reversal in a tag question that gives a binary choice. Then you can use whichever response they choose, reframing as necessary to make it seem this is what you intended all along.
You: You like chocolate, don't you?
You: You like chocolate, don't you?
This may cause a moment's confusion where they pause. It can be important here to keep talking and move them on before they have time to challenge you.
Tag questions in their native form often add a negative reversal to statements, such as 'That's right, isn't it?' or 'It did happen, didn't it?'
This structure hides a command in a rhetorical question, telling the other person what to think, then adding a question that offers disagreement while implying this is not wanted (as to do so would be to argue against an already-made assertion).
A reason this works is because the first statement is stronger and hence is the major persuasive element. Reversing the negative can have a significant effect. Note how 'He's right, isn't he?' is clearly different in meaning to 'He's not right, is he?', although both are reversals.
The tone you use when making such statements will also change the likelihood of disagreement. If you pause between the two halves and have a more pronounced rising tone in the tag question (That's right ... isn't it?'), you may signal more uncertainty and so invite challenge. You can also use other emphasis to change how the words are interpreted.
Reversal tagging can also be used to persuade people to take action. This can take the same format as gaining agreement, so 'You can do it, can't you?' or 'You will, won't you?' embed commands in weakened opportunities to disagree.
An interesting reversal is to put the negative first, such as 'You can't do it ... Can you?' (with maybe a pause between). When you tell a person they cannot do something you set up a reactive dynamic where they feel insulted by the suggestion that they are incapable, and so pounce on the tag with a response such as 'Of course I can!'
A further use of reversal tagging is to make statements that allow you to appear right, no matter what the response. The basic principle is that because you are making two opposing statements, you can choose the one that you 'really meant'. For example if you say 'You are happy, aren't you?', then you can reply 'I thought so' whether the response is 'yes' or 'no'.
Some reversal tag statements will have more influential first parts, for example 'You are happy, aren't you?' pushes for agreement that the person is qualified. This power can be weakened by swapping the negation, so 'You aren't happy, are you?' makes it easier for the other person to feel less pressure about their choice. This can be useful when testing for something about which you are not sure. For example if you say 'You are married, aren't you?' then it can be awkward if they say 'no'. saying 'You aren't married, are you?' is more tentative and allows for wise nodding if they say they are not married and mild surprise or delight if they say they are.
This method is often used by mentalists and 'mystics' who pretend to read your character or predict the future. So rather than saying 'You have a sister' they may say 'You have a sister, don't you?' Then whatever their response, they can say 'I thought so.' While they are suggesting you have a sister, the tag question provides an escape route if you say that you do not.