To George Mason University they came, more than 40 of them from as far away as Florida and California, to reflect on the 1930s, the Depression and how it shaped their lives.

They were among more than 50,000 senior citizens who will participate in national Elderhostel programs this year on more than 500 college and university campuses in the 50 states and abroad.

In this reintroduction to academic life for people over age 60, topics for study range from bacteria to architecture, from regional history to acid rain.

The program works because a growing population of senior citizens is seeking affordable and meaningful recreation, said Michael Zoob, vice president of the Boston-based nonprofit group.

And colleges, he added, are eager to use facilities that would otherwise lie dormant in the summer. Zoob said the program had grown nearly threefold since 1979.

Most of the senior students, who paid $180 each for a week of cafeteria cuisine and dormitory life, came to George Mason as eager to offer their views and experiences as they were to learn.

"What comes to mind when you think of the 1930s?" Lorraine Brown asked her students gathered in the Fenwick Library conference room.

"Insecurity," said one. "Frustration," said another. "Poverty." "Prohibition," said yet another and everyone laughed.

The class discussion grew serious, at times even heated, as the participants hashed through the events that took America from the stock market crash to the opening of the New York World's Fair.

In particular, they focused on the theater and literature that guided the era. As a focal point they used the archives of the Federal Theatre Project, a federal program that created jobs for artists from 1935 to 1939. The archives are at George Mason.

Lectures, further discussions, a field trip to the Smithsonian Institution, a performance of several vignettes from the Spoon River Anthology and a play at the Kennedy Center also were scheduled for the week.

During one discussion, Brown could hardly complete a sentence without a number of hands jutting skyward to signal a difference of opinion or some facet yet unmentioned.

"I remember a feeling of patriotism, understanding. If the Depression were to happen today, they'd burn the place the country down," said one gentleman with a dark, pencil-thin mustache.

"Naw," retorted others. "That's not so." "They've lived through this decade," Brown said afterward. "They have some life experience and they have opinions. Eighteen-year-olds are not political in the way that these people are.

"They might not agree with you, but they are going to fight with you. And that's the most rewarding type of teaching," Brown said.

Some hostelers said they had come to George Mason in combination with visits to friends or relatives in Northern Virginia. Others, like Dr. and Mrs. Max Slater of Bradenton, Fla., spend most of the summer hostel-hopping.

"This is our fifth, with three more to go," said Mrs. Slater, dressed in a T-shirt, shorts and sneakers.

"You can't compare a resort to a college," Max Slater said. "This is so beautiful. And where are you going to find a library at a resort?"

Herman and Bess Fein of Philadelphia agreed. The George Mason program was the ninth one they have been to in six years. Recently they studied Appalachia at Morehead (Ky.) State University.

Virginia Polytechnic Institute and State University in Blacksburg is scheduled to offer programs on Charles Dickens, the future and problem solving Aug. 14 to 27. The University of Virginia, the University of Maryland at College Park and Virginia Commonwealth University also held Elderhostel programs this summer.