[Question] What social movements can EA be compared to?

I’ve seen some EAs mentioning the possibility of tractable research that compares EA to other social movements and looks for trends that might reveal some things about EA, whether in the present or in the future. (See Effective Thesis—I also thought I saw something on an Open Phil agenda about this, but wasn’t able to find it.)

I think EA is unique from many, if not most historical social movements and hence difficult to compare with, most notably because of its relative breadth (having one very broad goal and several cause areas beneath that). But I’d find it hard to be convinced that EAs can’t learn anything at all from trends in other social movements.

My two questions are: a) how useful might comparing EA to other social movements be, and b) are there any particular social movements that look similar to EA?