I’m sure this is old hat to many people, but it just struck me the other day.
When I’m discussing topics about which I have in-depth or professional knowledge, I am generally much more positive in the tone of my discussion. So that’s translation, teaching, and poetry. If I see comments about these in professional forums, they’re usually very civil anyway. If I see comments about them in non-professional, general forums, they may be not civil or negative, but I almost never react in a negative way. I think the reason is just that I have lots of experience in these areas and remember not understanding them, so I can relate to what the commenters might think. If the person making the comment is a professional/has lots of experience, then I’m not tempted to argue; I just want to listen and learn. If the commenter doesn’t have that in-depth knowledge, then I can recognise their level, and respond in a more constructive way: either give them some of the background information that they’re missing, or just ignore them.
When I’m discussing topics about which I don’t have professional levels of knowledge, this response doesn’t kick in, and I am more often tempted to argue. Politics is the obvious one. If someone says something I disagree with on a political topic, I might want to rebut, and sometimes I want to do so in a personalised way.
Is there a solution? Should I read lots of politics textbooks and attain a professional level of knowledge? Will that make me not want to argue any more? Dunno. Perhaps more realistic would be to try to take the virtues of professionalism and apply them to other areas of life.