In 1970, the photographer Susan Meiselas, then a graduate student at Harvard, started making portraits of her fellow boardinghouse residents for a class project. She shot them in their bedrooms, generally posed in a corner, and managed to make a somewhat random group of people — a jovial law student, an anxious schoolteacher, a self-serious engineer — into a convincing microcosm of society, or at least of Cambridge, Mass.

After developing her film and printing contact sheets, glossy black rectangles in which her earnest graytone images floated like bubbles, she also asked her subjects to look at themselves and respond in writing.

These contact sheets and handwritten letters, displayed in alternation in “44 Irving Street 1970-1971,” make for one of the clearest presentations I can recall of the central paradox of self-expression. Gordon is watchful, Joan hugs her knees to her chest, and Don half conceals himself in a doorway. But those very postures expose more about their moods and personalities than if they had just stood up and smiled.

In their letters, Don is frank and disillusioned, while Alease, the anxious schoolteacher, says just what she thinks she’s supposed to, but there’s as much personality in their idiosyncratic handwriting as in anything they do or don’t say. The juxtaposition of image and writing only serves to emphasize how much each form leaves hidden. The more they reveal, the more they conceal — and vice versa.