I'd like to suggest adding a description to the profile. E.g. I would like to mention that I am male, so people are not thinking I'm pretending to be female.

I also considered an option of adding a "male" flair, but maybe it's an overkill, as in my opinion content of the arguments should be the first thing to consider and not characteristics of the person arguing. And if one wants to check the details about the person, one can see the profile, so I think it's a good compromise.

EDIT:

Besides the flair (always visible) and the description in the profile (which requires clicking and changing the page) another option in between those two would be a small panel which appears when you move your mouse over the user name and which can contain some info about the person.

Also instead of text description which might encourage creating profiles and doxing, as one of the other users described below, it might also just be a simple checkbox.