In literature, round characters are characters that have deep and complex personalities, while flat characters are simple and uncomplicated.

In James Thurber's popular short story "The Secret Life of Walter Mitty," the protagonist, Walter Mitty, may be classified as a round character, mostly due to his complexity. Some might argue that he's actually a flat character, as he is continuously weak, passive, and submissive for most of the story, and the only character development that actually happens, happens in his daydreams or in his imagination. In "reality," he essentially remains the same. However, the fact that he even has these daydreams shows that he is somewhat imaginative and that his character is actually not as simple or as boring as it seems.

Thus, a better question is whether Walter Mitty is a dynamic or a static character.

Dynamic characters are usually in conflict with themselves and/or other characters and therefore undergo character development, while static characters don't change and remain the same to the very end.

Thurber doesn't really develop Walter's character much; he presents him as someone who is in conflict with himself, jumping from one fantasy to the other in order to protect his true self, but also as someone who remains unchanged throughout most of the story. Walter doesn't develop greatly or significantly, but he does become more assertive and bolder and stands up to his wife near the end of the story. When his wife angrily tells him that she's been looking for him all over the hotel and asks him where he was, he confronts her (which is atypical for him), saying,

Does it ever occur to you that I am sometimes thinking?

Despite this assertiveness, however, he is still as predictable and as uninteresting as always. Thus, he can be classified as a static character. In conclusion, Walter Mitty is a round but static character; his character may be complex, but it remains undeveloped.

In James Thurber's story "The Secret Life of Walter Mitty," are Walter and Mrs. Mitty "round" or "flat" characters and are they dynamic or static?

“Round” characters in fiction are complex; “flat” characters are simple. “Dynamic” characters develop in some significant ways during the course of a work; “static” characters do not.  Are the main characters in James Thurber’s story “The Secret Life of Walter Mitty” flat and static, or are they round and dynamic? One might presume that the characters in Thurber’s comic story are more flat and static than they are round and dynamic, but the story is worth a closer look.

Of the two characters, Mitty seems rounder and more dynamic.  After all, Mrs. Mitty appears in the story only during brief intervals, and her personality doesn’t seem to change or develop much, even by the standards of a brief comic tale.  She is pretty much the same nagging wife at the end of the story as she was at the beginning.

Mitty, on the other hand, shows considerable imagination and inventiveness; his fantasies are diverse and lively; he even invents other interesting people to populate them; and, even though his fantasies reflect his familiarity with various popular narrative genres (and are in that sense predictable), they suggest that Mitty is a far more complex character than his wife.  We see far more sides of Walter’s mental make-up than we see of Mrs. Mitty’s.

By the same token, Mitty can be said to develop in some ways during the course of the story.  Although he moves from one fantasy to the next, he becomes a bit more assertive by the end of the tale than he had been at the beginning, especially when he asks his wife,

"Does it ever occur to you that I am sometimes thinking?"

Here he stands up for himself – if only briefly and quietly – in a way he had not done earlier, when he seemed far more passive.

Mitty also seems to develop as a character in the sense that by the end of the story he is imagining not only his bravery but also his possible death:

Then, with that faint, fleeting smile playing about his lips, he faced the firing squad; erect and motionless, proud and disdainful, Walter Mitty the Undefeated, inscrutable to the last.

This sentence – the final sentence of the tale – suggests, perhaps, that Mitty may be suffering more deeply from his rather hum-drum ordinary life than was suggested at first.  Earlier Mitty had been mainly a cause for laughter (and perhaps also some empathy) in the reader.  By this point in the tale, however, a more serious, ominous, slightly disturbing element creeps in. The final sentence is tinged with a bit of poignant irony and adds some real complexity not only to Mitty’s character but also to the story itself.

Few people would claim, of course, that the Mittys are anywhere nearly as complicated and dynamic as, say, the characters in Faulkner novel. They were never meant to be.  But neither are they as flat and static as they could have been, and this is particularly true of Walter Mitty, whose imagination allows him to achieve a kind of complexity he doesn’t display in “real” life.