You might wonder: why not an ampersand (&)? That’s for APA nerds. MLA loves the word "and." It’s friendlier. More human.
Imagine introducing two friends at a party. You’d say, “This is Alice and Bob.” Not “This is Alice & Bob.” See? Civility matters.
Fun fact: The ampersand was once a letter of the alphabet. Kids used to sing “X, Y, Z, and per se and.” The “and per se and” became “ampersand.” But MLA isn’t nostalgic. They insist on the full word.