We've all done it. We've gone to the wrong website in the wrong mood — or under the influence— and left angry scrawls in the comments. But we shouldn't, and not just because it makes us look stupid. This behavior actually strengthens the position of the people we're arguing against.
In fact, some recent experiments show that writing long angry political comments is an even worse idea than you'd think. When you make a badly-thought-out argument — and most angry comments consist of badly-thought-out arguments — you're strengthening the position of the person you're arguing against. It's called "inoculation," and it works just as well mentally as physically. Making a weak argument against someone's ideas give them not just a chance to shore up their arguments against that particular argument, but against stronger arguments as well. As one study found:
"The present study tested the hypothesis that preexposure to refutations of some counterarguments against the belief would have a generalized immunization effect, making the beliefs more resistant to strong doses not only of the specific counterarguments… but also of alternative arguments against the given belief… . As expected, the beliefs proved highly vulnerable to the strong counterarguments when there was no prior immunization. Immunization had a direct strengthening effect on the beliefs and also substantially reduced the effect of the subsequent strong counterarguments."
One really good, well-thought-out argument can make a person rethink their whole position on an issue. One weak argument will not only fail to convince them, but inoculate them, so any future, smarter arguments will fail as well.