NEW YORK — As other protesters chanted vigorously around her, Nancy Pi-Sunyer stood off to the side at the Occupy Wall Street rally, clutching her sign, looking a little like a new teacher on the first day of school.

NEW YORK — As other protesters chanted vigorously around her, Nancy Pi-Sunyer stood off to the side at the Occupy Wall Street rally, clutching her sign, looking a little like a new teacher on the first day of school.

In a way, she was: At 66, this retired teacher was joining a protest for the first time in her life. "I was too young for the civil rights movement," Pi-Sunyer said earlier this week as she joined thousands of protesters marching in lower Manhattan. "And during the Vietnam War, I was too serious a student. Now, I just want to stand up and have my voice be heard."

As the protests have expanded and gained support from new sources, what began three weeks ago as a group of mostly young people camping out on the streets has morphed into something different: an umbrella movement for people of varying ages, life situations and grievances, some of them first-time protesters.

There are a few common denominators among the protesters: their position on the left of the political spectrum, and the view that the majority in America — the "99 percent," in their words — isn't getting a fair shake.

Beyond that, though, there's a diversity of age, gender and race — in part due to the recent injection of labor union support, and fueled by social networks — that is striking to some who study social protests.

"Most people think this is a bunch of idealistic young kids," said Heather Gautney, a sociology professor at Fordham University and an analyst of social protests. "But the wider movement is remarkably more diverse than it's been portrayed. I've seen a lot of first-time protesters, nurses, librarians. At one protest, the younger element seemed actually to be in the minority."

Pi-Sunyer, who lives in Montclair, N.J., was drawn into the fray on Wednesday the same way many were — via social networks. She saw a post from a friend on Facebook and realized it was time to join.v