Saying you need a job to pay rent may be the honest answer, but it's probably not the best answer when interviewers ask you why you want to join their company or institution, Nature Jobs reports.
Instead, it says that your response should highlight what the employer would get out of hiring you and what you'd get out of working there.
In other parts of the interview you should've covered why you're qualified and would do well in the position. In answering this question, though, Nature Jobs says you need to show you actually find the job interesting. It suggests thinking back to when you saw there was an opening and what sparked your interest in applying in the first place. "[F]ind whatever you genuinely found interesting about them and talk about that," it says.
As for the second part of your response, think about what new skills and knowledge you'd acquire by working there. Nature Jobs notes that many employers are now interested in personal development and so you can discuss what parts of your scientific skill set you'd be able to hone there.
"Overall, this question is a great opportunity to demonstrate how you're a good choice for the role — not just because you have the skills to do well, but because you genuinely care about the work," Nature Jobs adds. "Show how you care about them, and why they should care about you."