On a committee to evaluate people across all fields, I was the representative for many of the STEM fields. That I was a mathematician came up frequently at our meetings. During the week, we came in at our convenience to read files.
One day, X, Y, and I were sitting around the table in the file room. As we read files, X and Y chatted amiably. They laughed about how all mathematicians are poorly dressed. And how mathematicians hold their glasses together with tape. I tried to ignore them.
Eventually, the insults reached a level where I didn't feel comfortable keeping quiet. In as friendly a voice as I could muster, I said "Some of the people in my department dress quite well."
X shot back, "Yeah, right! Name one!"
I looked down at my clothes. By pure luck — or more truthfully, my awareness that the better I dressed with this committee, the better the candidates I represented fared in the committee's evaluations — I happened to have been quite well dressed that day. I gestured towards my clothes, but they didn't get the hint.
Did they intend to deliberately insult me?
I don't think so. I think it's more likely that they didn't think of me as a mathematician (or maybe even as an academic). I wondered whether the STEM candidates we evaluated would have fared better with a man representing them, well-dressed or not.
I named a mathematician — a former Dean — who dresses nicely. They expressed doubt, and continued their chatter.
After I finished reading files, on my way down in the elevator, a well-dressed woman complimented me profusely on my lovely outfit. I smiled, and wished X and Y had been there. But I still don't know what I should have done to make them remember that I'm a mathematician.