I've talked about brain-washing techniques before; here are a few more examples to watch for when debating online:

"that's not how you engage in productive conversation."

This is trying to make you question your thinking, ask yourself what you said/did wrong. 1/ https://twitter.com/TabithaK/status/1327739247294558211

Maybe you did say something wrong. Check yourself. But if you didn't, don't fall for the person who is just trying to make you question yourself. This is the first point.

Next is the "I told you..."

This is saying that you're not listening or not remembering. 2/

Maybe they did tell you & you missed it. Go back and check. But if they did NOT tell you, then maybe they honestly thought that they did, or maybe they're trying to get you to question your own thoughts/memory.

This is again a means of making you question yourself. 3/

The goal of gas-lighting is to make you question yourself. If you don't believe yourself, then of course no one else should believe you either. If someone can make you question yourself, you're far less likely to convince anyone, let alone yourself, that you're right. 4/

Remember: yes, you could be wrong. But when someone is using underhanded techniques to make you question your own thinking rather than giving arguments to make you question your position, DO NOT fall for it.

Some people do this unintentionally; with others, it's intentional. 5/

If you see signs once, give the person the benefit of the doubt. Twice? Maybe question their motives. Three or more in a single thread? Point it out. Most who are doing it intentionally will run away when it's pointed out, or they'll double-down, making it more obvious. 6/6