How can I make a generic protagonist feel real and motivated under pressure?

[RonaldND]

I'm outlining a novel and have a solid plot structure, but my protagonist feels like a generic vehicle for the story rather than a real person. I've filled out character questionnaires, but they haven't helped me understand her deeper motivations or how she would authentically react under pressure. For writers who struggle with flat characters, what exercises or perspectives shifted your approach to character development, helping you discover the unique voice and contradictions that make a character feel alive on the page?

[Sophia.R]

Try a 'pressure test' exercise: put your protagonist in a small, unrelated crisis and write 300–500 words from her POV. Focus on what she clings to, what she hides, and how her body language shifts when the stakes creep upward. The key is not the outcome but what the reaction reveals about her values and reflexes.