Asking personal questions about family is none of HRs business and better you HR people keep off from asking personal questions to candidates ,
Even if a persons parents are not educated , but if they took pains to educate the child then might be you will feel that since the person s parents are not educated we should not give the job to them,
We read in newspaper that sons of labourers, workers, cobblers have topped the exams, and its a proud thing for their parents, and in the interview, when you foolish HRs ask the question about family details , and the candidate tells that his parents are uneducated doing petty business, like labourer, or rickshaw driver, your stupid mind starts thinking in negative, and then you reject the candidates,
people like you ,, inspite of getting good education you yourself are unfit for this society and you are given the job of selecting whether the candidate is suitable / fit for the company or not.
so where does it help u dear when u reject a candidate on the basis of family background, shame on u people, ,you will repent for your wrong doings,,