How do I keep research honest when there's pressure to bend the results?

You have decided that the truth comes before the reward, the deadline, or the person hoping for a certain answer. That is a rare and serious stand. Lives will be treated based on what you find, so honesty here is not a personal virtue only. It is care for people you will never meet. The pressure will not announce itself. It comes as a nudge to overlook one odd result, to frame things a little more favorably, to not ask the hard question. Each nudge feels small. Holding firm through all of them is what your integrity actually looks like day to day. When you feel the pull to bend, name it out loud, even just to yourself: this is the incentive talking. Then set it aside and follow the evidence. Do that enough times and it stops being a struggle and becomes who you are.