Illegal interview questions are a minefield for job seekers. You may choose not to work for a company with employees who ask these questions, it could say some pretty negative things about their culture, but, then again, it may just be one uninformed person for a job you think you will love. When asked about Race, Color, Sex, Religion, National Origin, Birthplace, Age, Disability or Marital/Family Status, you have three options.
You can refuse to answer and inform the interviewer their question is at a minimum improper and probably illegal. You will be right, but winning this battle probably means you lose the job.
You can compromise your privacy and your ethics and answer the question. You won’t be happy, but your viability for the job probably continues.
Instead of directly answering the question, answer the concern that prompts the question.
Chances are the illegal questions won’t be as obvious as, “How old are you?” or “Do you have children?” They might talk about their children and see if you commiserate or say they know someone from your college and ask if you graduated the same year. Good defusing answers would be commenting on the picture of their family on their desk or saying that family friendly companies are good places to work but you are most interested in the responsibilities of this position as it seems a great fit. For the age/college question, you could comment how much you loved your alma mater and hope that the friend had as good an experience as you did, or does the interviewer know anyone else who went there?
Gracefully avoiding the question and steering your conversation elsewhere is a great tactic. Redirecting the question to your interviewer and keeping your answers to the illegal questions short and general work well, too.
If your interviewer isn’t disarmed from their pursuit of a specific answer to an illegal question, you may have to resort to, “Can you help me understand how this question is relevant to the position?” or “I’m confident I can handle the requirements of this position.” But, remember to keep you tone light and engaging. Most of these questions are asked accidentally or without nefarious intent, so acting with diplomacy is a credit to your interview ability and to your hireability.