Short answer: Persistence, humility.
Longer answer: I have worked in both mathematics departments and math education departments, and I think there are a few striking differences:
Department meetings in mathematics are much more concise.
Disagreements among my math colleagues tend to be much more about issues, among math ed colleagues things tend to get personal.
For some reason, the math groups I have been with are much more social; and have much better habits, such as afternoon teas; and meet socially outside of the university.
Mathematicians tend to be better at asking and receiving help. (Perhaps because of 1-3 above? Also perhaps because at the end of the day are actually are right answers :-))