After four days of standing behind a booth and watching a sea of mathematicians flow around me, I've come up with some completely unverifiable and yet undoubtedly true observations:
1. 76% of all male mathematicians over the age of 55 have remarkably long beards.
2. 76% of all male mathematicians under the age of 40 have remarkably long ponytails.
3. Many of the male mathematicians between the ages of 40 and 55 have both beards and ponytails. They are in a transitory phase.
4. I saw a few young male mathematicians who wore their ponytails up high on their head. (Think more "cheerleader" than "sensitive smart guy"). I found this was a disturbing trend and I hope it stays underground.
5. Maybe about 30% of mathematicians are women of varying ages. I found them generally hard to generalize.
6. Mathematicians will go crazy for chocolate. I put a few pieces on top of my candy dish of hard candies whenever the crowd around me dwindled, and it rocketed business back up. I saw grown men pick through my candy dish for chocolate, and then take a few pieces without saying hi, asking me about my display, or taking one of my brochures. At least take a brochure, dudes. Seriously.
7. Despite all these semi-snarky fashion statements, mathematicians are the most friendly, polite, weird, and socially unusual group I've ever been around, with the possible exception of librarians. In fact, I think the two populations have a lot in common: They both attract vaguely "nerdy" individuals, they both encourage extreme specialization and knowledge of arcane subjects, and in both professions you can pretty much wear whatever you want all the time.
Strangely enough, the mid-winter conference for the American Library Association is being held in San Antonio this week, just one week after the mathematics conference. San Antonio is being overrun by friendly geeks!