“Is it okay to ask about personal matters if they relate to the job?”
This could be a very short blog. The answer is “No, it isn’t.” Personal matters are just that – personal. For instance, if you’re planning to hire a female, can you ask her if she’s planning to have children someday? NO! Can you ask her about her marital status or her plans to get married? NO! Can you ask any candidate about his/her overall health? NO! All three of those questions fall under headings that are encompassed by the provisions of the Civil Rights Act of 1964, as amended.
“But,” you say, “I don’t want to hire someone who’s going to miss a lot of work because of a pre-existing illness or a female who is going to go on maternity leave for weeks at a time!” At some level, those might seem like reasonable questions to ask, but if you do ask questions about health or marital status, you’re directly violating federal law, and you’re asking for a federal discrimination lawsuit to be filed against you.
How people live their lives and what they do on their own time is none of the employer’s business – unless how they live or what they do on their personal time will adversely affect their ability to do the job for which they’re hired.
The way to deal with this problem is, at the end of the conversation, ask references a question like this: “Do you have any other concerns that could affect so-and-so’s ability to do the job for which he’s being considered?” Then, depending on the answer – and the answers other references give to the same question – the employer will have to decide if the problem, whatever it happens to be, is significant enough to disqualify the candidate from further consideration for the job to be filled.